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On the physical oceanography of Burrard Inlet and Indian Arm, British Columbia Davidson, Laurie Wayne 1979

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ON THE PHYSICAL OCEANOGRAPHY OF BURRARD INLET AND INDIAN A R M : B R I T I S H COLUMBIA  by  LAURIE WAYNE DAVIDSON B.Sc.(Hon),  University  of B r i t i s h Columbia,  A T H E S I S SUBMITTED IN P A R T I A L THE REQUIREMENTS  FULFILLMENT  FOR THE DEGREE OF  MASTER OF SCIENCE i n  THE FACULTY OF GRADUATE STUDIES in  THE DEPARTMENT OF  PHYSICS  and THE  INSTITUTE  OF OCEANOGRAPHY  We a c c e p t t h i s t h e s i s a s c o n f o r m i n g to  the required  standard  THE UNIVERSITY OF B R I T I S H COLUMBIA February, ©  Laurie  1979  Wayne  Davidson  1973  OF  In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l for that  an advanced d e g r e e a t the L i b r a r y  study. this  shall  I further  thesis for  department  the U n i v e r s i t y  make i t  agree that  permission for  this  thesis for  w i t h o u t my w r i t t e n p e r m i s s i o n .  Faculty  of  Vancouver, V6T Date  Oceanography  Graduate  The U n i v e r s i t y  of  Canada  1W5 9 March  British  freely available for  o r by h i s r e p r e s e n t a t i v e s .  of  of  the  requirements  Columbia,  I  1979  Studies  British  Columbia  It  extensive copying  i s understood that  financial  agree  r e f e r e n c e and of  s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e Head o f  or p u b l i c a t i o n of  Institute  f u l f i l l m e n t of  gain shall  not  my  copying  be a l l o w e d  i i ABSTRACT Measurements o f t h e d i s t r i b u t i o n s o f t e m p e r a t u r e , oxygen  in Burrard  to October  and I n d i a n A r m , B r i t i s h  i n t h i s system.  Observations  w e r e s u p p l e m e n t e d by s e r i a l  a few h o u r s ,  Short-term tidal shown t o be s m a l l  Circulation  CSTD c a s t s  f l u c t u a t i o n s in property  taken over currents,  in the Burrard  Inlet  -  I n d i a n Arm s y s t e m i s  r e l a t i v e l y f r e s h surface waters  from the S t r a i t o f  basically  Georgia.  flow through  and Second Narrows y i e l d s  sense,  a r e f r e s h e r and w a r m e r .  bottom waters  exchange and o v e r t u r n  o f deep w a t e r  r e c o r d e d b e t w e e n O c t o b e r 1974 a n d A p r i l have o r i g i n a t e d w e s t o f F i r s t  Narrows.  l e a s t 80% o f t h e v o l u m e o f t h e A r m , o v e r i n f e r r e d from property  1975.  the  surface  b e t w e e n t h e n a r r o w s w h i c h a r e more s a l i n e a n d c o o l e r t h a n i n a simpler estuarine environment.  111%  been  n o r m a l l y f l o w down t h e i n l e t  m i x i n g a s s o c i a t e d w i t h e s t u a r i n e and t i d a l  Significant  of  temperature,  d i s t r i b u t i o n s have  w h i c h w o u l d be f o u n d  to  intervals  compared t o s e a s o n a l c h a n g e s .  s h a l l o w c o n s t r i c t i o n s a t both F i r s t waters  four-week  sill.  o v e r l y i n g more s a l i n e w a t e r s w h i c h e n t e r Turbulent  at roughly  a n d by 9 3 - d a y r e c o r d s o f n e a r - b o t t o m  a n d s a l i n i t y o n t h e I n d i a n Arm  estuarine:  C o l u m b i a f r o m May 1974  1975 h a v e b e e n a n a l y s e d t o d e t e r m i n e f e a t u r e s o f t h e l a r g e  scale circulation intervals  Inlet  s a l i n i t y and  those  In a complementary  i n I n d i a n Arm was  I n t r u d i n g w a t e r s were  shown  In one i n s t a n c e exchange o f an i n t e r v a l  o f 33 d a y s , was  d i s t r i b u t i o n s , compared t o exchange e s t i m a t e s  and 74% d e d u c e d f r o m t h e c u r r e n t m e t e r r e c o r d f o r t h e same  of  event.  at  i i i E x c h a n g e was shown t o into  Indian  density factors.  of  Arm,  tidal  Georgia  be i n t e r m i t t e n t , mixing  Strait  with  (particularly  water  being  f r e s h water at  runoff  Second Narrows)  i d e n t i f i e d a s some o f  the  volume and controlling  iv TABLE OF  CONTENTS Page  ABSTRACT  i i  L I S T OF TABLES  vii  L I S T OF FIGURES  vii i  ACKNOWLEDGEMENTS CHAPTER 1  xii  INTRODUCTION  1.1  General  1.2  Physical  1.3  Historical  CHAPTER 2  AND OVERVIEW  1  D e s c r i p t i o n of Study  1  D e s c r i p t i o n o f the Study  Area  3  Review  1.3.1  General  1.3.2  Burrard Inlet  1.3.3  I n d i a n Arm  DATA COLLECTION  8  Review  8 9 10  AND REDUCTION  13  2.1  The F i e l d Program  13  2.2  Instruments  16  2.3  Secondary Data Sources  18  2.4  Data Reduction Techniques  19  2.5  Resultant  22  CHAPTER 3  and Methods  Data Base  SHORT PERIOD T I D A L FLUCTUATIONS  3.1  General  3.2  Reference Tidal  3.3  Fluctuations 3.3.1  IN PROPERTY DISTRIBUTIONS  Description of Tides  24  Curves  25  a t P e r i o d s L e s s T h a n 12 H o u r s  S t a t i o n s Van 1 1 - 1 ,  24  Van 1 1 ,  Van 1 1 - 5 ,  25 Van 11-8  26  V Page  3.4  CHAPTER 4 4.1  4.2  3.3.2  S t a t i o n s Van 17,  V a n 24  30  3.3.3  S t a t i o n s Van 2 7 , Van 3 4 , Ind 0  33  3.3.4  S t a t i o n V a n 11  35  Summary  36  ANCILLIARY  INFORMATION  37  M e t e o r o l o g i c a l Parameters  37  4.1.1  Precipitation  37  4.1.2  A i r Temperature  38  4.1.3  Winds  39  Runoff  41  SEASONAL CHANGES IN WATER PROPERTY D I S T R I B U T I O N S  45  5.1  Surface Behaviour  45  5.2  Overview t o Annual  CHAPTER 5  5.3  CHAPTER 6 6.1  i n Approaches Cycles  54  5.2.1  Temperature  55  5.2.2  Salinity  58  5.2.3  Oxygen  65  Detail  of Annual  Cycles  71  CURRENT METER MEASUREMENTS  103  T i m e - S e r i e s C u r r e n t Meter Record  103  6.1.1  Location,  103  6.1.2  Time-Series of Currents  6.1.3  T i m e - S e r i e s o f Temperature  T i m i n g and Data R e c o v e r y  104 and S a l i n i t y  106  vi Page 6.2  Averaged  T i m e - S e r i e s Current Meter Record  6.2.1  Averaging  108  6.2.2  T i m e - S e r i e s of Averaged  Currents  6.2.3  T i m e - S e r i e s of Averaged  Temperature  6.3  Relation of Current  6.4  Deduced V e r s u s M e a s u r e d I n f l o w 6.4.1  Method  6.4.2  Preparatory  6.4.3  Inflow January  6.4.4  6.4.5  CHAPTER 7  108  108 and S a l i n i t y . . .  Meter Record to Property  Distributions  Volumes  109 110 112 112  Assumptions and C a l c u l a t i o n s  Interval  D e c e m b e r 2 9 , 1974 t o  2 4 , 1975  Inflow Interval M a r c h 1 , 1975  113  114 January  27,  1975 t o 116  Summary a n d D i s c u s s i o n  118  SUMMARY  121  7.1  Summary o f M a j o r O b s e r v a t i o n s  121  7.2  Potential  127  LITERATURE APPENDIX FIGURES  Further  Investigations  CITED  I PHOTOGRAPHIC DYE-TRACKING STUDY.  '.'.,,.,..,..«  129 132 137  vii L I S T OF TABLES Page  2.1  Summary o f C r u i s e s  6.1  Summary o f Volume C o m p a r i s o n s  14 118  vi i i L I S T OF FIGURES Page 1.1  Maps o f B u r r a r d  1.2  L o n g i t u d i n a l depth p r o f i l e s o f ( b ) I n d i a n Arm  3.1  3.2  3.3  3.4  3.5  3.6  3.7  3.8  3.9  3.10  3.11  3.12  3.13  Inlet  and I n d i a n A r m , showing s t a t i o n l o c a t i o n s  138  (a) B u r r a r d I n l e t and 139  Empirical t i d a l curves (representative of Burrard showing " t i d a l b i n " d e f i n i t i o n s .  Inlet  tides) 140  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 1 1 - 1 , A u g u s t 2 8 , 1975  and (b) temperature  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 1 1 , A u g u s t 2 8 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 1 1 - 5 , A u g u s t 2 8 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 1 1 - 8 , A u g u s t 2 8 , 1975  and (b) t e m p e r a t u r e a t  C o m p a r a t i v e t e m p e r a t u r e and s a l i n i t y A p p r o a c h e s , J u l y 2 5 , 1975  at 141  142  143  144 p r o f i l e s from Burrard  Inlet 145  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 1 7 , A u g u s t 2 6 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 2 4 , A u g u s t 2 6 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 2 7 , A u g u s t 2 7 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s of (a) s a l i n i t y Van 3 4 , A u g u s t 2 7 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s o f (a) s a l i n i t y Ind 0 , A u g u s t 2 7 , 1975  and (b) temperature  Time-depth s e c t i o n s of (a) s a l i n i t y Van 1 1 , A u g u s t 1 9 , 1975  and (b) t e m p e r a t u r e a t  Time-depth s e c t i o n s o f (a) s a l i n i t y Van 1 1 , S e p t e m b e r 3 , 1975  and (b) t e m p e r a t u r e a t  146  147  148  149 at 150  151  152  ix Page 4.1  S e a s o n a l v a r i a t i o n o f ( a ) p r e c i p i t a t i o n and ( b ) a i r temperature at s t a t i o n s surrounding Burrard I n l e t  153  S e a s o n a l v a r i a t i o n o f ( a ) m o n t h l y mean w i n d s p e e d and ( b ) d a i l y mean w i n d s p e e d a t s t a t i o n s s u r r o u n d i n g B u r r a r d I n l e t .  154  S e a s o n a l v a r i a t i o n o f mean m o n t h l y r u n o f f f r o m ( a ) F r a s e r R i v e r a t M i s s i o n and ( b ) C a p i l a n o R i v e r , Seymour R i v e r and B u n t z e n Power H o u s e s  155  5.1  (a)  156  5.1  (b) Surface d i s t r i b u t i o n of A p p r o a c h e s , A u g u s t 1 , 1974  4.2  4.3  5.2  5.3  5.4  5.5  5.6  5.7  5.8  5.9  5.10  5.11  5.12  Station  locations in Burrard  Inlet  density  Approaches  (Sigma-t)  in Burrard  Inlet 156  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and B u r r a r d I n l e t A p p r o a c h e s , A u g u s t 1 , 1974  (b)  S u r f a c e d i s t r i b u t i o n s o f ( a ) s a l i n i t y and B u r r a r d I n l e t A p p r o a c h e s , A u g u s t 2 9 , 1974  (b)  temperature  in 157  temperature  in 158  S u r f a c e d i s t r i b u t i o n s o f ( a ) s a l i n i t y and ( b ) B u r r a r d I n l e t A p p r o a c h e s , F e b r u a r y 2 2 , 1975  temperature ,  in  S u r f a c e d i s t r i b u t i o n s o f ( a ) s a l i n i t y and B u r r a r d I n l e t A p p r o a c h e s , May 3 0 , 1975  (b)  temperature  in  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and B u r r a r d I n l e t A p p r o a c h e s , J u n e 1 3 , 1975  (b)  S u r f a c e d i s t r i b u t i o n s o f ( a ) s a l i n i t y and B u r r a r d I n l e t A p p r o a c h e s , J u l y 2 5 , 1975  (b)  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and B u r r a r d I n l e t A p p r o a c h e s , A u g u s t 1 9 , 1975  (b)  159  160 temperature  in 161  temperature  in 162  temperature  in 163  S u r f a c e d i s t r i b u t i o n s o f ( a ) s a l i n i t y and ( b ) B u r r a r d I n l e t A p p r o a c h e s , S e p t e m b e r 3 , 1975  temperature  S u r f a c e d i s t r i b u t i o n s o f ( a ) s a l i n i t y and ( b ) B u r r a r d I n l e t A p p r o a c h e s , O c t o b e r 1 0 , 1975  temperature  in 164 in 165  T i m e - d e p t h s e c t i o n s o f t e m p e r a t u r e , May 1974 t o O c t o b e r 1975 s t a t i o n s ( a ) Van 11 ( b ) Van 24 ( c ) Van 34 ( d ) I n d 1 and (e) Ind 2 T i m e - d e p t h s e c t i o n s o f s a l i n i t y , May 1974 t o O c t o b e r 1975 s t a t i o n s ( a ) Van 11 ( b ) Van 24 ( c ) Van 34 ( d ) I n d 1 and (e) Ind 2 ,  at 166  at 168  X  Page 5.13  5.14 5.15  Time-depth sections of oxygen, May 1974 to October 1975 at stations (a) Van 11 (b) Van 24 (c) Van 34 (d) Ind 1 and (e) Ind 2  170  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, May 14, 1974  172  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, July 17, 1974  174  5.16  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, August 27, 1974... 176  5.17  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, August 27, 1974  178  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, October 16, 1974  180  5.18 5.19  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, November 7, 1974.. 182  5.20  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, November 7, 1974  184  5.21  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, December 5, 1974.. 186  5.22  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, December 6, 1974  188  5.23  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, January 23, 1975.. 190  5.24  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, January 23, 1975  192  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (di) oxygen for Burrard Inlet, February 19, 1975.  194  5.25 5.26  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, February 21, 1975..... 196  5.27  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, March 26, 1975  198  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Burrard Inlet, April 29, 1975  200  Longitudinal sections of (a) temperature (b) salinity (c) sigma-t and (d) oxygen for Indian Arm, April 30, 1975  202  5.28 5.29  xi Page 5.30  5.31  5.32  5.33  6.1  6.2  6.2  6.2  6.3  6.4  6.5  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , J u n e 1 3 ,  1975  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , A u g u s t 1 8 ,  204  1975...  206  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t a n d ( d ) o x y g e n f o r I n d i a n A r m , A u g u s t 1 8 , 1975  208  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , O c t o b e r 9 ,  1975...  210  D e t a i l o f t e m p e r a t u r e and s a l i n i t y r e c o r d s from n e a r - b o t t o m c u r r e n t m e t e r o n I n d i a n Arm s i l l , s h o w i n g i n t e r v a l s o f p o s s i b l e instrument malfunction  212  (a) T i m e - s e r i e s o f n e a r - b o t t o m c u r r e n t s o n I n d i a n Arm December 5 , 1974 t o J a n u a r y 4 , 1975  sill, 213  (b) T i m e - s e r i e s o f n e a r - b o t t o m c u r r e n t s o n I n d i a n Arm J a n u a r y 5 , 1975 t o F e b r u a r y 4 , 1975  sill,  (c) T i m e - s e r i e s o f n e a r - b o t t o m c u r r e n t s o n I n d i a n Arm F e b r u a r y 5 , 1975 t o M a r c h 7 , 1975  sill,  214  T i m e - s e r i e s o f t e m p e r a t u r e and s a l i n i t y a t c u r r e n t meter on I n d i a n Arm s i l l , December 5 , 1974 t o J a n u a r y 4 , 1975 T i m e - s e r i e s of averaged near-bottom December 5 , 1974 t o M a r c h 7 , 1975  215 site  c u r r e n t s on I n d i a n Arm  216 sill, 217  T i m e - s e r i e s o f a v e r a g e d t e m p e r a t u r e and s a l i n i t y a t c u r r e n t m e t e r s i t e on I n d i a n Arm s i l l , December 5 , 1974 t o M a r c h 7 , 1975  218  1-1  Geometry  219  1-2  T r a n s f o r m e d p o s i t i o n s o f d y e l i n e s , F e b r u a r y 9 , 1976 a t ( a ) 1147 P S T , ( b ) 1402 P S T , ( c ) 1441 PST a n d ( d ) 1 5 2 0 PST  220  Cross-channel v e l o c i t y p r o f i l e s , February  221  1-3  of coordinate t r a n s f o r m a t i o n  9,  1976  xi i ACKNOWLEDGEMENTS The  extensive  possible only of  f i e l d program r e p o r t e d  through  the voluntary  i n t h i s t h e s i s was made  donation  o f n e a r l y 200 m a n - d a y s  s h i p t i m e by numerous c o l l e a g u e s a t t h e I n s t i t u t e  and b y v a r i o u s sincere  thanks,  Mark E k e l u n d ship  personal with  friends.  The  Defence  is gratefully  to  Albert  dependable companions.  t i m e by t h e C a n a d i a n H y d r o g r a p h i c  National  Oceanography  To a l l who p a r t i c i p a t e d I  p a r t i c u l a r commendation  who w e r e r e g u l a r ,  of  extend  Fuller  and t o  The d o n a t i o n  of  S e r v i c e a n d by t h e D e p a r t m e n t  of  acknowledged.  CSTD s y s t e m was on l o a n f r o m M r . A l A g e s  of the I n s t i t u t e  of  Ocean S c i e n c e s , P a t r i c i a B a y : c o n s i d e r a b l e a s s i s t a n c e i n k e e p i n g t h e instrument  operational  I was g r e a t l y  was r e n d e r e d by D r . J i m S t r o n a c h .  a s s i s t e d i n d e s i g n i n g and c o n d u c t i n g t h e dye s t u d y  by t h e p h o t o g r a p h i c  e x p e r t i s e o f M r . P a t Wong.  l o a n e d by D r . J . F . R .  Gower o f t h e I n s t i t u t e  Bay a n d by M r . P a r k e r  Various  e q u i p m e n t was  o f Ocean S c i e n c e s , P a t r i c i a  Williams of Integrated  Resource Photography  Ltd.,  Vancouver.  I w i s h t o e x p r e s s my t h a n k s interest  in this project,  handling  the c u r r e n t meter  throughout  t h e work  Particularly lasting  through  Steve  Pond f o r h i s l a s t i n g  and f o r h i s p e r c e p t i v e a d v i c e , record.  and o f f e r e d  Dr.  G.L.  substantial  particularly in  P i c k a r d a s s i s t e d by e x a m p l e comments on t h e m a n u s c r i p t .  I am i n d e b t e d t o my s u p e r v i s o r D r .  patience,  friendship.  to Dr.  R.W. B u r l i n g f o r h i s  h i s t e c h n i c a l d i r e c t i o n , h i s d e t a i l e d e d i t i n g and h i s  The w o r k was s u p p o r t e d  by NRC G r a n t A 5 3 7 4 t o D r .  B u r l i n g and  t e a c h i n g a s s i s t a n t s h i p s i n t h e D e p a r t m e n t o f P h y s i c s , UBC.  xi i i As t h e w r i t i n g was d o n e a f t e r express  a p p r e c i a t i o n t o my e m p l o y e r ,  for  the understanding  The  c o n t r i b u t i o n s of  S o n i a Brown i n t y p i n g  p r o v i s i o n of Peter Thuerig  a n d t o my c h i l d r e n J e f f r e y , sacrifices years.  and f o r  Fenco  Institute,  Consultants  t i m e and o f  their  Ltd.  I  must of  Calgary  secretarial assistance.  i n c o m p l e t i n g t h e g r a p h i c s and  and e d i t i n g a r e m o s t g r a t e f u l l y  Most s i g n i f i c a n t l y I express  few  leaving the  sincere gratitude  K a t i e and W a r r e n f o r  appreciated.  t o my w i f e  their  c o n s t a n t g e n t l e encouragement  of  Katherine  unselfish through  the  past  1 CHAPTER 1  INTRODUCTION  1.1  General  D e s c r i p t i o n o f Study  In t h e p a s t 30 y e a r s ,  numerous  i n l e t s of the southern  C o l u m b i a c o a s t h a v e b e e n s t u d i e d and r e p o r t e d from the I n s t i t u t e  o f Oceanography,  by P i c k a r d ( 1 9 6 1 a n d 1 9 7 5 ) , and F a r m e r ,  1972),  Knight  Inlets  1975),  Pendrell  Bell,  attention  Vancouver  for  Beyond t h e g e n e r a l  (Buckingham, 1977).  1962),  Inlet  Waldichuk e t al_. (1968)  Despite  by T a b a t a  Motivated  by t h i s  J e r v i s and  ( B e l l , 1973;  t h e s e many p r o j e c t s ,  (1971)  identifies typical  t h e a r e a b u t does n o t d i s c u s s  Bute,  ( T u l l y , 1949;  1 9 7 6 ) a n d Howe S o u n d ,  has been p a i d t o t h e w a t e r s  of Burrard  Inlet  overviews  1957; M a c N e i l l , 1974; and L a f o n d ,  Harbour system l o c a t e d so near that  description of  ( T a b a t a and P i c k a r d , Sound  o n , many by r e s e a r c h e r s  these include Alberni  I n d i a n Arm ( G i l m a r t i n  1974; and B u c k l e y ,  little  UBC.  British  of the Burrard Institute.  Inlet  -  The  b a s e d upon t h e d a t a summer a n d w i n t e r  t r a n s i t i o n s between  lack of information  relatively  these  f o r t h e Vancouver  report  conditions  seasons.  area,  t h e p r e s e n t p r o j e c t was c o n c e i v e d i n t h e s p r i n g o f 1974 t o p r o v i d e a thorough  documentation  and s y n o p t i c d i s c u s s i o n o f t h e p h y s i c a l  oceanographic parameters planning  stages  p r o j e c t would  of the Burrard  i t was d e t e r m i n e d  that  Inlet  system.  In t h e e a r l i e s t  the geographical  i n c l u d e I n d i a n Arm a s w e l l  w h i c h t h e Arm i s c o n n e c t e d t o t h e S t r a i t  as B u r r a r d of Georgia.  p o r t i o n of t h i s study which deals e x p l i c i t l y with  scope of t h e  Inlet  through  Thus,  while the  I n d i a n Arm may b e  v i e w e d a s a s c a l e d down r e p e t i t i o n o f some o f G i l m a r t i n ' s w o r k , is  unique  Burrard  in i t s presentation with  Inlet  and w i t h  s i m u l t a n e o u s measurements  some r e l e v a n t  information  it  from  on c u r r e n t s o v e r t h e  2 sill  at  t h e mouth o f  present  study  I n d i a n Arm.  i s an e x p a n s i o n w i t h  on t h e d i s t r i b u t i o n its  of p r o p e r t i e s ,  consideration of  treatment  The  of  deep w a t e r  goal  of  this  region over  a period of  about that  the  large  exchanges  at  least  so,  between  occurred in  to estimate  the  spatial  Through a s e r i e s of a 93 d a y c u r r e n t m e t e r accomplished.  The  p r o g r a m and p r e s e n t  the extent  of  chapters the  the  its  Indian  to  i n the  study  annual  infer It  information was  appropriately  thought selected  information  and S e c o n d  midrwinter period of s c a l e s of  Arm.  of  about  Narrows. exchanges  such  above o b j e c t i v e s  resultant  This  a s i g n i f i c a n t volume of  results.  data.  through  A  First  useful  However,  I.  of  was field  secondary  Narrows  data  using  pursued to  a successful  and i s d e s c r i b e d i n A p p e n d i x  and  exchanges.  p r o j e c t was n o t of  of  observations  and s e c t i o n s d e s c r i b e t h e  dye t r a c k i n g t e c h n i q u e .  t e c h n i q u e was d e v e l o p e d  if the  t o measure c u r r e n t s  included i n the p r e s e n t a t i o n  analysis,  o c e a n o g r a p h i c c r u i s e s and t h e a n a l y s i s  an a n a l y s i s o f  generating  at  place in F i r s t  r e c o r d each of  following  p r o j e c t was a t t e m p t e d a photographic  27  identify  i n the a r e a .  and t e m p o r a l  and  and  l e a s t some q u a l i t a t i v e  I n d i a n Arm d u r i n g  effects  seasonal  concentration to  the  tidal  the d i s t r i b u t i o n  s u c h as t h e s e ,  could also y i e l d at  of  harbour  and t h e r e b y  scale c i r c u l a t i o n pattern  work,  properties  the  12 m o n t h s ,  i t was a l s o d e s i r e d t o d e t e r m i n e  deep w a t e r if  i t s more t h o r o u g h  i n these p r o p e r t i e s ,  the mixing processes which take Finally,  investigations  and d i s s o l v e d o x y g e n  t i m e - s e r i e s measurements  locations,  its  p r o j e c t was t o m o n i t o r  salinity,  changes  r e l a t i o n to Tabata's  surface d i s t r i b u t i o n s of  temperature,  cyclical  In  be  to  3 1.2  P h y s i c a l D e s c r i p t i o n of the Study  Small Figures  a n d l a r g e s c a l e maps o f t h e s t u d y a r e a a r e p r e s e n t e d a s  1.1(a)  positions  and 1 . 1 ( b ) .  S i g n i f i c a n t p l a c e names a r e n o t e d a l o n g  a n d names o f t h e o c e a n o g r a p h i c s a m p l i n g s t a t i o n s .  be n o t e d t h a t  d i s s o l v e d oxygen  identified  3481  on F i g u r e  i s to  approx-  These a r e s y m b o l i c a l l y  1.1(b).  c o n v e n t i o n i n t r o d u c e d on C a n a d i a n H y d r o g r a p h i c  The t e r m " B u r r a r d  (excluding  Inlet"  Service charts  i s used t o r e f e r t o t h e e n t i r e  area  I n d i a n Arm) e x t e n d i n g f r o m P o i n t A t k i n s o n t o t h e head o f t h e  n e a r t h e t o w n s i t e o f P o r t Moody.  divisions  (a)  with  a n d 3484 i s e m p l o y e d h e r e i n i d e n t i f y i n g t h e r e g i o n s o f t h e s t u d y  area.  inlet  It  c o n c e n t r a t i o n was m o n i t o r e d a t  i m a t e l y one h a l f o f t h e sample l o c a t i o n s .  The  Area  Within Burrard  Inlet,  sub-  a r e i d e n t i f i e d as f o l l o w s :  Vancouver Harbour: from P o i n t A t k i n s o n F a l s e Creek  Approaches - that to F i r s t  Narrows,  region extending  eastward  i n c l u d i n g English Bay.  i s c o n s i d e r e d t o be a d i s t i n c t body o f  water  e x t e n d i n g e a s t w a r d from t h e B u r r a r d B r i d g e , and i s n o t t r e a t e d in  (b)  this  Vancouver Second  (c)  study.  Harbour:  West - t h a t  r e g i o n e n c l o s e d between  F i r s t and  Narrows.  Vancouver Harbour: Second Narrows  Central  to Burn's  - that  Point  region extending eastward  and n o r t h w a r d  I n d i a n Arm t o t h e v i c i n i t y o f s t a t i o n  Ind 0 .  a t t h e mouth  of  from  4 (d)  Vancouver Harbour:  East -  that  extending eastward from B u r n ' s  In t h e at  following text,  extending northward  Port  fjords.  Inlet,  Moody  etc.  from s t a t i o n  Ind 0 t o  it  present.  lengths  f r o m a mean w i d t h o f  The w i d t h o f  km w i d e c o n s t r i c t i o n a t km.  the  6.9 First  Narrows  beyond B u r n ' s  Burrard (Figure  Inlet  1.2(a))  at  Indian  water River.  Atkinson  Columbia c o a s t a l of  respects.  other  coastal  Particularly fjords  its  through  the  the western harbour  with  km w i d e c o n s t r i c t i o n  h a r b o u r w h i c h has a mean w i d t h  Point,  lies  exhibits a shallow,  the e a s t e r n  i r r e g u l a r depth  which i s d i s t i n c t l y d i f f e r e n t Outside  u n i f o r m l y f r o m a maximum d e p t h o f sill  the  body o f  of  harbour  km w i d t h .  Columbia c o a s t a l i n l e t s .  outer  into  Through a second 0.7  1.3  c h a r a c t e r i z e d by a 0 . 9  British  km i n t h e a p p r o a c h e s ,  opens the c e n t r a l  Further,  may  approaches",  i n l e t varies greatly along  a t Second Narrows km.  Harbour"  the steep mountain w a l l s a s s o c i a t e d w i t h  are not  1.9  typical  f r o m t h e s e i n many o t h e r  along the south s h o r e ,  Moody.  e a s t w a r d 3 0 . 6 km f r o m P o i n t  l o n g narrow shape r e s e m b l e s t h a t  differs  a mean w i d t h o f  the d e l t a of  inlet  t h e v a r i o u s r e g i o n s a r e now d e s c r i b e d .  which extends  its  the  I n d i a n Arm i s d e f i n e d a s t h a t  i s not r e p r e s e n t a t i v e of  Although  embayments,  0.6  through Port  the d e s i g n a t i o n "Vancouver  physical c h a r a c t e r i s t i c s of  Burrard to  Point  t i m e s be d e l e t e d and t h e r e g i o n s r e f e r r e d t o a s " t h e  "the western harbour",  The  remaining portion of  the Narrows.  First 110  from t h a t  Narrows,  m off  profile o f most  British  the bottom s l o p e s  Point Atkinson  to  the  In t h e w e s t e r n h a r b o u r a r e o b s e r v e d  quite 14 m  the  5 deepest hole  (66 m j u s t  bank  (Loch K a t r i n e  sill  a t Second Narrows  depth. rises  Finally, quite  east of  Bank a t  16 m)  i s found  uniformly  to  the  the c r o s s channel  shallow, Point  another  narrow  passages at  in contrast to  rather  at  the  east of  Arm,  Narrows  than  a symmetrical  fresh water  typical  First  the n o r t h .  most o f  the  source at Narrows,  around P o i n t  the head.  the  to  discharge into  Burrard peripheral  the  factor  Inlet  this area.  First  the western  Second Narrows  a r e s i g n i f i c a n t s o u r c e s i n Lynn Creek  harbour. to  from  Narrows  Secondary  McKay and  a small  in  Apart  do s o  the west are V i n s o n ,  Creeks provide  Fraser  this  harbour.  j u s t west of  River  region.  influence of  G o d m a n and C y p r e s s C r e e k s .  Burn's  Fraser  t h e N o r t h Arm o f  streams e n t e r i n g Burrard  g r e a t e s t volume d i s c h a r g e i n t o  Rodgers,  of  Grey i s a major  i n the Narrows,  inlet,  Most s i g n i f i c a n t  distributions in this  sources entering progressively f u r t h e r Macdonald,  input from  i s the e f f e c t  The C a p i l a n o R i v e r w h i c h e n t e r s  the  and  B r i t i s h Columbia f j o r d ,  i t s f r e s h water  the  very  distinct regions.  source i s a l s o i d e n t i f i a b l e i n the western  Fraser,  the  i t s four  from a major  by m i x i n g  Moody.  U-shaped  into  surface layer property  tempered  60 m  where  Second N a r r o w s ,  the  18 m  bottom  head i n P o r t  Second  the  to  the  Narrows,  Water d i s c h a r g i n g p r i m a r i l y t h r o u g h  controlling  provides  Beyond  First  Inlet  and s w e e p i n g n o r t h e a s t w a r d s  from the  Indian  profiles generally exhibit  in the approaches, o u t s i d e  Although  Narrows.  a s u b s t a n t i a l d i s t a n c e across the  receives e f f e c t i v e l y a l l of  water.  shallowest  i s seen then from the above d e s c r i p t i o n s t h a t  Again  sources,  and t h e  depression extending  flats  the area j u s t  separate Burrard  Inlet  inside First  tidal  s h a l l o w booming grounds e x t e n d  It  Shoal)  e a s t w a r d f r o m t h e mouth o f  With the e x c e p t i o n of  form.  Burnaby  Lawson,  Mosquito Spanning  t h e w e s t and  the  6 Seymour R i v e r  to the east.  Second Narrows  Occasional small  creeks enter  between  and t h e h e a d , b u t do n o t c o n s t i t u t e a m a j o r  In a l e s s  d i r e c t sense,  source of  f r e s h water  source.  I n d i a n Arm i t s e l f m u s t be c o n s i d e r e d a s a  i n p u t to the Burrard  Inlet  system.  Estimates  input rates are presented i n s e c t i o n 4.2 with a d i s c u s s i o n of effects  of  f r e s h water  No c o l l e c t i o n  that  the general  sand.  Tabata,  bottom  however,  composition of  Organic material  the  may be o f  with  Fraser  River  inlet floor  of  its long,  km f r o m t h e mouth a t  1.3  km.  2.2  station  t r a n s e c t near the c e n t r e of  fjord.  The Arm  the  coupled with  0.5  km i s o b s e r v e d o f f north  extends  Hamber  Island  near Raccoon I s l a n d a  The d e p t h p r o f i l e a l o n g a l o n g i t u d i n a l  the f j o r d  i s i l l u s t r a t e d in Figure  inlet.  The  horizontal  1.2(b)  shallow  the presence of  constriction  a shallow s i l l  s u g g e s t s a p r o b a b l e p h y s i c a l impedance to c i r c u l a t i o n between B u r r a r d  of  25 m n e a r t h e mouth a n d t h e maximum d e p t h  220 m n e a r t h e m i d d l e o f  waters  that  I n d 0 t o t h e h e a d , w i t h a mean w i d t h  where the s i g n i f i c a n t f e a t u r e s w h i c h appear a r e the v e r y  Hamber I s l a n d ,  notably  There i s a suggestion  as a t y p i c a l  km i s n o t e d .  depth of approximately  c l a y and  the p h y s i o g r a p h i c s t r u c t u r e  while s l i g h t l y further  maximum w i d t h o f  silty  n a r r o w s h a p e s u r r o u n d e d by s t e e p l y s l o p i n g  A minimum w i d t h o f  near the mouth,  i s mud,  data,  origin.  Inlet,  mountain w a l l s i d e n t i f i e s i t 21.5  performed  h a s b e e n o b s e r v e d i n some l o c a t i o n s ,  In c o n t r a s t t o B u r r a r d Indian Arm,  s e d i m e n t s was  comments f r o m W a l d i c h u k ' s  n e a r t h e B r o c k t o n P o i n t Sewer O u t f a l l . the s i l t  the  input.  or analysis of  during t h i s survey.  of  Inlet  sill of off  in this  and e x c h a n g e  o u t s i d e and t h e u p p e r r e a c h e s o f  area of  Indian  Arm t o w a r d s  the  such exchange in  fact  take  head.  as  the  (b)  numerous  (d)  River  small  B u n t z e n Power of  from the  l a r g e volume  that  while  exchanges  input  to  Indian  Arm  Houses  at  the  head o f  the  do  are  fjord  streams which c u m u l a t i v e l y  remainder  f r e s h water  #1  of  the  and # 2 ,  surrounding  through  account  watershed  which  are d i s c h a r g e d from Buntzen  controlled Lake  precipitation.  As m e n t i o n e d ,  the  in Section  Gilmartin  clays,  f r e s h water  peripheral  the  sediments  5 and 6 )  conditions.  which enters  input  considered  r e s t r i c t e d , major  sources of  for  direct  (Chapters  follows:  Indian  amounts  be shown  p l a c e under c e r t a i n  (a)  (c)  will  i s normally  Four primary identified  It  in  deals  Indian  s i g n i f i c a n c e of  the  various  sources  is  4.2.  i n some d e t a i l Arm,  and some o r g a n i c  with  the d i s t r i b u t i o n of  and i d e n t i f i e s t h e material.  presence of  sands,  bottom silts,  8 1.3  Historical 1.3.1  In  Inlet  Review  and I n d i a n  three  overview  early  summary  works.  with  Also  temperature,  The f i r s t  chlorinity,  In a l a t e r w o r k , oceanographic  Indian  concentration  gives  into  little  input.  fjords  Columbia c o a s t .  southern  A further  term v a r i a t i o n s  B r i t i s h Columbia  Indian Arm. identified  treatment  of B r i t i s h  i n l e t s according to t h e i r  from g l a c i e r s .  Although  paper  average  i n the p r o p e r t i e s inlets,  a generally  i n a given  shown t o be d i s r u p t e d to m a j o r deep w a t e r  (1975)  o f 13 y e a r s  inlet,  with of  d i s c u s s e s annual in  basins,  various including  c y c l e o f c h a n g e was of data,  by o c c a s i o n a l l a r g e c h a n g e s ,  exchanges.  inlet  of i t s fresh  o f deep w a t e r s  r e g u l a r annual  input  of the B r i t i s h  passages and c o a s t a l  f o r t h e Arm f r o m a t o t a l  of the  The p h y s i c a l d i m e n s i o n s  by P i c k a r d  of  Columbia.  and volume  for fjords  of  Georgia.  f r e s h water  distributions of properties  t h e Arm a r e s l i g h t l y s m a l l e r t h a n  and l o n g e r  of  I n d i a n Arm i s i d e n t i f i e d a s a medium r u n o f f  o r no c o n t r i b u t i o n  is  these  f o r a number  the S t r a i t  a thorough  i n l a r g e m e a s u r e e x p l a i n e d by t h e n a t u r e  water  fjords  d e s c r i p t i o n of the d i s t r i b u t i o n  of the coastal  the various  to  ( 1 9 3 4 ) i n w h i c h an  of B r i t i s h Columbia  Arm) w h i c h o p e n (1961)  be g i v e n  concerning the o r i g i n of  and n u t r i e n t  and shows how t h e o b s e r v e d are  features  is a brief  Pickard  features  He c a t e g o r i z e s  i s that of Carter  some s u g g e s t i o n s  presented  (including  r e v i e w o f o c e a n o g r a p h i c work i n  Arm, c o n s i d e r a t i o n should f i r s t  of physiographic  together  features.  fjords  General  p r e s e n t i n g an h i s t o r i c a l  Burrard  given,  Review  likely  this  c y c l e was  attributable  9 1.3.2  Burrard  From 1949 Fraser for  River  1951)  1951,  Estuary  the Vancouver  Included  of  to  Inlet a number o f  and D i s t r i c t s J o i n t  are temperature, in Burrard  observations locations  with  Waldichuk P o r t Moody  are  and r e c o r d e d t i d a l  curves  from  (1965),  i n v e s t i g a t i o n of  these data First  number current  lateral circulation in  to generate Narrows.  his plots  These  of  he f o u n d  i n h i s paper d e a l i n g w i t h water  a reasonably  and c i r c u l a t i o n o f  r e g i o n which i s not  to date.  a r e summarized as  thorough the  treated  in detail  of  treatment  head w a t e r s  region east of  As n o t e d e a r l i e r , t h e w o r k  (a)  a  inlet.  in his  b a s i c e m p h a s i s i s on t h a t  treatment  Group,  report  depths,  Group  average to  compare  theoretically predicted distributions.  provides  oceanography  ( P a c i f i c Oceanographic  included in this  Also  distribution outside  favourably  entire  Board.  Inlet.  surrounding the  (1954),  report  Sewage a n d D r a i n a g e  data for  an i n l e t e m p l o y e d some o f salinity  the  s a l i n i t y and d i s s o l v e d oxygen  from v a r i o u s  Campbell  of  w e r e c o n d u c t e d by t h e P a c i f i c O c e a n o g r a p h i c  i n the r e s u l t a n t data  stations  oceanographic surveys  of  of  exchange  in  the p h y s i c a l  Burrard  Inlet.  His  t h e p r e s e n t s t a t i o n Van 3 9 ,  in this  Tabata  The m a j o r o b s e r v a t i o n s  a  thesis.  (1971)  i s the most  and c o n c l u s i o n s o f  complete his  work  follows:  F r e s h W a t e r S o u r c e s : The d r a i n a g e a r e a o f I n d i a n Arm ( i n c l u d i n g d i s c h a r g e t h r o u g h t h e two B u n t z e n Power H o u s e s ) , t h e d r a i n a g e a r e a o f B u r r a r d I n l e t , and t h e F r a s e r R i v e r a r e i d e n t i f i e d as three s i g n i f i c a n t sources of fresh water. The f o r m e r two  c o n t r i b u t e t o t h e e s t a b l i s h m e n t o f an e s t u a r i n e c i r c u l a t i o n pattern. T h i s p a t t e r n may be w e a k e n e d o r d i s r u p t e d by t h e presence of Fraser R i v e r water j u s t o u t s i d e F i r s t Narrows. The e f f e c t of d i r e c t p r e c i p i t a t i o n i n d i l u t i n g surface s a l i n i t y i s e s t i m a t e d t o be a p p r o x i m a t e l y 10% t h a t o f r u n o f f . (b)  H e a t B u d g e t : The b a l a n c e o f p h y s i c a l p r o c e s s e s a s s o c i a t e d w i t h heat i s such t h a t "most o f the heat energy s t o r e d i n the i n l e t d u r i n g the h e a t i n g season i s r e l e a s e d back to the atmosphere d u r i n g the c o o l i n g s e a s o n " .  (c)  T i d a l C u r r e n t s : T i d a l c u r r e n t s o f s p e e d s up t o 6 k n o t s a r e a s s o c i a t e d w i t h F i r s t and Second N a r r o w s : a s y s t e m o f e d d i e s coupled w i t h these c u r r e n t s i s i d e n t i f i e d i n the harbour. These " c u r r e n t s a r e c o n s i d e r e d as t h e d o m i n a n t a g e n c y c o n t r i b u t i n g t o the m i x i n g of waters i n the i n l e t " .  (d)  S a l i n i t y , T e m p e r a t u r e , O x y g e n D i s t r i b u t i o n : The s e a s o n a l o b s e r v a t i o n o f r e l a t i v e l y h i g h s u r f a c e s a l i n i t y i n w i n t e r and r e l a t i v e l y l o w s u r f a c e s a l i n i t y i n summer i s e x p l a i n e d i n t e r m s of f r e s h water input c y c l e s . Deeper w a t e r s a l i n i t y v a r i e s l e s s o v e r a n a n n u a l c y c l e and i s c o n s i d e r e d t o be c o n t r o l l e d somewhat by m i x i n g p r o c e s s e s i n t h e N a r r o w s . Temperature d i s t r i b u t i o n i s c h a r a c t e r i z e d by a t y p i c a l summer c a s e a n d a t y p i c a l w i n t e r case. D i s t r i b u t i o n o f d i s s o l v e d o x y g e n i s c l a i m e d t o be c o u p l e d c l o s e l y to b i o l o g i c a l processes i n the i n l e t . There i s a r e l a t i v e l y h i g h oxygen c o n t e n t i n B u r r a r d I n l e t . Annual f l u c t u a t i o n s a r e shown t o be s m a l l .  (e)  T u r b i d i t y and Water Q u a l i t y : Waters i n B u r r a r d I n l e t a r e t y p i c a l l y v e r y t u r b i d e x c e p t i n e a r l y w i n t e r n e a r t h e mouth I n d i a n Arm. Areas of the system ( e . g . the western harbour) do n o t m e e t s t a n d a r d s o f w a t e r q u a l i t y s u i t a b l e f o r p u b l i c b a t h i n g : o t h e r a r e a s m a r g i n a l l y meet t h e s e s t a n d a r d s . 1.3.3 Due  Indian  to  its  Indian  Arm  typical  Arm has b e e n t h e  oceanographic  surveys.  physical  oceanography  (1962).  His major  summarized.  of  fjord  nature,  s i t e of  and i t s  several  to  Vancouver,  b i o l o g i c a l and p h y s i c a l  The m o s t c o m p r e h e n s i v e and c i r c u l a t i o n o f  proximity  treatment  t h e Arm i s g i v e n  of by  the Gilmartin  r e s u l t s c o n c e r n i n g c i r c u l a t i o n i n t h e Arm a r e  now  11 (a)  A n a l y s i s of suggestions  sediment d i s t r i b u t i o n patterns regarding c i r c u l a t i o n :  leads to  some  b a s e d on p r o g r e s s i v e s o r t i n g o f s e d i m e n t s a l o n g t h e f j o r d i n b o t h n o r t h e r l y and s o u t h e r l y d i r e c t i o n s , two s e d i m e n t sources (water sources) are i d e n t i f i e d ; the Indian R i v e r e n t e r i n g a t t h e h e a d , and i n t r u d i n g w a t e r s f r o m B u r r a r d I n l e t e n t e r i n g a t the mouth. b a s e d on c r o s s c h a n n e l d i s t r i b u t i o n s , i t i s s u g g e s t e d t h a t water e n t e r i n g the f j o r d flows inward along the e a s t e r n s i d e w h i l e t h a t l e a v i n g the f j o r d flows outward along the western s i d e . non-stagnant conditions p r e v a i l , i n d i c a t i n g a f r e q u e n t r e p l e n i s h m e n t o f deep w a t e r . (b)  A b a s i c e s t u a r i n e c i r c u l a t i o n i s documented w i t h t h e i m p o r t a n t c o n t r o l l i n g f e a t u r e s b e i n g i d e n t i f i e d as t h e c y c l e of f r e s h w a t e r i n p u t , t h e s i l l d e p t h and w a t e r p r o p e r t y ( p a r t i c u l a r l y d e n s i t y ) d i s t r i b u t i o n s o u t s i d e the s i l l . E x c h a n g e o f i n t e r m e d i a t e and deep w a t e r i s e v i d e n t f r o m t h e p r o p e r t y d i s t r i b u t i o n s . Superi m p o s e d upon t h e b a s i c e s t u a r i n e c i r c u l a t i o n a r e t i d a l e f f e c t s . A t i d a l j e t theory i s suggested to e x p l a i n the presence of narrow tongues of i n t r u d e d water observed i n the near s u r f a c e l a y e r b e t w e e n d e p t h s o f a b o u t 20 m and 40 m. T i d a l mixing i n the n a r r o w , s h a l l o w c h a n n e l o f f Hamber I s l a n d i s c o n s i d e r e d t o be of s i g n i f i c a n c e i n determining the c i r c u l a t i o n p a t t e r n .  A number McHardy  case,  of  (1961),  also monitored their  intrusions to  relatively  b i o l o g i c a l researchers besides G i l m a r t i n , Shan  (1962),  physical  Regan  parameters  as p a r t  of  dense water  into  t h e Arm.  e v i d e n c e d even  i n the deepest  The m e c h a n i s m o f fjords.  shallow-silled  deep w a t e r  Lazier  (1963)  fjords.  The  their  have  In  each  mid-winter  Some s u c h c h a n g e s a r e  seen  column, while others  are  water.  exchange  has b e e n i n v e s t i g a t e d  has s u g g e s t e d a t i d a l behaviour  (1974)  surveys.  evidence of  the water  bottom  and W h i t f i e l d of  p h y s i c a l d a t a c l e a r l y show t h e  be v e r t i c a l l y c o n f i n e d w i t h i n  other  (1968),  notably  of  jet  the j e t water,  mechanism  in for  once a c r o s s  the s i l l  i s determined  o c c u r when t h e upward  the  monitored channel  i n t r u d i n g water  indigenous frequent  and B u t e  when w a t e r  at  by i t s d e n s i t y .  bottom w a t e r .  corresponding water  for  outside  inside.  e s t i m a t e d the volume o f magnitudes  More r e c e n t l y ,  over a two-year  depths  the  replenishment  can  s u f f i c i e n t density to d i s p l a c e  i n t e r m e d i a t e and deep w a t e r  Inlet  sill  i s of  Deep w a t e r  period.  Lafond  (1975)  intrusions into Intrusions  budget methods,  Sutil  occurred  i n l e t became more d e n s e  Using property  than  Lafond  t h e s e i n t r u s i o n s and s u g g e s t e d p o s s i b l e  the a s s o c i a t e d c u r r e n t s .  has  has  CHAPTER 2 DATA COLLECTION 2.1  The F i e l d  AND REDUCTION  Program  T h r o u g h o u t t h e p e r i o d May 1 4 , 27 o c e a n o g r a p h i c These  i n length  of c r u i s e s .  generally  apart  intense  Auxilliary  Figure  1,  1.5,  Table  the time  gaps,  that  1.1(b).  t h e c r u i s e s were  by t h e C a n a d i a n PARIZEAU,  Stations  supplementary  sampled l e s s  11-8,  Van 1 1 ,  commencing w i t h  sets of stations  regularly  months.  S e r v i c e on  R e s e a r c h B o a r d on C a n a d i a n  14,  17,  s e t , i n the area outside 11-5,  11-1,  14-10,  Ind 1 . 3 ,  Forces  is illustrated  3 4 , 39 a n d I n d 0 ,  (station  Cruise 74/31).  First  spatial  V a n 14-8 was  I t was  attempted  a t l e a s t once p e r c r u i s e .  were a l s o e s t a b l i s h e d :  14-5, 14-2,  2 . 5 , 2.8 a n d 3 .  24, 27,  stations  i n conjunction with  w h i c h p r o v i d e d more i n t e n s i v e stations  i n columns 2  a n d RICHARDSON a n d t h e M o t o r  to occupy each o f t h e s e p r i n c i p a l s t a t i o n s  Van  as a  separated  Hydrographic  d i s t r i b u t i o n of sampling s t a t i o n s  2 were s e l e c t e d as "main l i n e "  auxilliary  a typical  i s presented  information  survey.  V e s s e l s LAYMORE a n d ENDEAVOUR.  added t o t h i s group  Two  2.1  with  conducted i n the winter  a n d by t h e D e f e n c e  geographic  in  than  S h i p s VECTOR,  PANDORA I I ,  to 4 days,  for this  of  The summer s a m p l i n g p r o g r a m was n o t  t i m e was p r o v i d e d  Canadian Survey  The  i s seen from  by 3 t o 4 w e e k s .  Ship  duration.  f r o m two 6 - w e e k  s i g n i f i c a n t l y more  Vessel  It  1975 a t o t a l  to c o l l e c t data  from 7 hours  e x c u r s i o n being o f 1 t o 2 days  and 3 t h a t  1974 t o O c t o b e r 1 6 ,  c r u i s e s were u n d e r t a k e n  c r u i s e s ranged  summary  13  these  t h e main l i n e . Narrows,  17-8  coverage  The f i r s t  included  and 1 7 - 5 . i n Indian  A summary o f s t a t i o n s  were  stations  The s e c o n d s e t , Arm, included sampled on each  14  TABLE  2.1 I  SUMMARY OF CRUISES 3 DAYS SINCE LAST CRUISE  2  1 CRUISE #  DATES  4  5  6  i  /  NUMBER OF STATIONS APPROACHES IND ARM MAIN (1) (2) LINE (3)  C T M b  m  COMMENTS (#=TIMES SAMPLED) (X=NOT SAMPLED)  74/17  14 May  -  11  -  74/19  25 Jun  42  14  -  74/24  17 J u l  22  18  -  74/26  31 J u l -  1 Aug  14  20  9  —  74/28  27 Aug - 29 Aug  26  23  9  2  14(2), 17(2), 24(2), 27(3), 34 3 11(2), 14(2), 17(2), 24(4), 27(4) 1 1 ( 2 ) , . 1 4 ( 2 ) , 1 7 ( 6 ) , 24(6)  «  14(2), 24(2),  34(2),  74/29A  9 Sep  13  8  -  ~  11(X), 1.5(X),  74/29C  11 Sep  2  10  -  1  1.5(X)  74/31  26 Sep  15  12  -  ~  Commenced 14-8 as main l i n e  74/32  ' 1 6 Oct  20  12  -  2  74/34  7 Nov  22  12  -  3  74/35  25 Nov  18  12  -  ~  74/36  5 Dec  10  11  -  2  27(X) C u r r e n t meter deployed  75/01  3 Jan  29  9  -  ~  27(X),  75/03  23 Jan  20  12  -  2  C u r r e n t meter s e r v i c e d  75/05  19 Feb  27  11  -  2  14-8(X)  75/06  22 Feb  3  4  8  75/08  7 Mar  13  12  -  75/11  26 Mar  19  12  -  2  75/13  29 Apr  34  12  -  2  75/18  30 May  31  12  8  75/20  13 Jun  14  12  8  75/25  24 J u l - 25 J u l  41  16  8  75/27  18 Aug - 19 Aug  25  16  8  75/28  25 Aug - 28 Aug  7  61  28  39(X),  2(X)  1.5(X)  Sampling o u t s i d e F i r s t Narrows o n l y C u r r e n t meter recovered  ~  2  11(2), 14(2), 14-8(2),  17(2)  11(2), 14(2), 14-8(2),  17(2)  CSTD c a s t s o n l y  75/29  2 Sep -  3 Sep  8  16  8  11(2), 14(2), 14-8(2),  17(2)  75/31  9 Oct - 10 Oct  37  16  8  11(2), 14(2), 14-8(2),  17(2)  7  12  ~  75/32  16 Oct  (1) Main l i n e ,  i n c l u d e s 12 s t a t i o n s ; 8 i n B u r r a r d I n l e t , 4 i n I n d i a n Arm  (2) F i r s t a u x i l l i a r y s e t ; i n c l u d e s 8 s t a t i o n s (3) Second a u x i l l i a r y s e t ; i n c l u d e s 4 s t a t i o n s  15 cruise  i s provided  i n Table 2.1,  columns 4 to  p a r t i c u l a r main l i n e s t a t i o n s were stations  were e x c l u d e d e n t i r e l y .  in  the s a m p l i n g program  of  a p a r t i c u l a r s t a t i o n are  in  brackets  by t h e  loss  by t h e  repeated.  On o t h e r s , of  i n c o l u m n 7.  repetitions.  It  some s u c h  indicates  the degree  of  The  followed  Main l i n e s t a t i o n s  i s observed  information  secondary  samplings  number,  that  not  number  the o n l y  o f main l i n e s t a t i o n d a t a o c c u r r e d on C r u i s e 7 5 / 0 1 ,  when 3 s t a t i o n s w e r e m i s s e d .  anomalies  Repeated  i n d i c a t e d by t h e s t a t i o n  "x".  cruises,  these  i n d i c a t e d by t h e s t a t i o n  number o f  letter  On some  A documentation  i s presented  s a m p l e d on a g i v e n c r u i s e a r e in brackets  7.  followed significant  January 3,  1975  i n c o l u m n s 5 and 6  s a m p l i n g w h i c h was c o n d u c t e d on e a c h  cruise.  To s u p p l e m e n t  the  information  gathered  i n the  p r o g r a m a r e c o r d i n g c u r r e n t m e t e r was d e p l o y e d (0.5  km s o u t h w e s t  March 7, the  1975.  of  Raccoon  Current  Island)  93 d a y  speed and d i r e c t i o n f o r  5,  Indian  1974  waters  i s provided  sampling  and  Arm  recovered  within  by t h e  sill  3 m of  resultant  record.  A second supplementary f r o m A u g u s t 25 t o temperature assess  on t h e  o n December  bottom a t a time of major exchange  property  1975,  to monitor  and s a l i n i t y o v e r  the s h o r t  Conductivity  28,  p r o g r a m was u n d e r t a k e n  -  term e f f e c t  salinity -  periods of of  tides  temperature  depth were t a k e n  repetitively  at  on t h e d i f f e r e n t  days o f  survey.  this  changes  depth  various  75/28,  i n the d i s t r i b u t i o n  a few h o u r s ,  on t h e -  on C r u i s e  property  and t h e r e b y  of  In a d d i t i o n ,  to  distributions.  (CSTD) c a s t s t o  groups  of  2 to  4  30 m  stations  on s e v e r a l  regular  cruises,  short  and 24.  The  measurements these data  At  time  interval  varied  to  2.2  t i m e - s e r i e s surveys  from  between  and  taken at  casts for  15 m i n u t e s  assess t i d a l  Instruments  were  to  stations  these assorted  nearly  2 hours.  influence i s presented  The  i n Chapter  recorded.  These  (a)  Meteorological  17  serial analysis  of  3.  Methods  each oceanographic s t a t i o n o c c u p i e d , a s e r i e s of  were  Van 1 1 ,  parameters  included:  parameters:  w i n d s p e e d and d i r e c t i o n barometric  pressure  wet and d r y cloud type  (b)  Oceanographic  bulb a i r and  temperature  cover  parameters:  wave h e i g h t  (visual  secchi  depth  disk  estimate)  vertical  d i s t r i b u t i o n of  temperature  vertical  d i s t r i b u t i o n of  salinity  vertical  d i s t r i b u t i o n of  d i s s o l v e d oxygen  (at  selected  stations).  The salinity Figure  basic oceanographic and o x y g e n  1.2.  approximately  program  concentration  Water  samples were  1.3  l i t r e capacity.  c o n s i s t e d of  sampling  at d i s c r e t e depths,  as i n d i c a t e d  collected in plastic N.I.O. Temperatures  temperature,  bottles  were d e t e r m i n e d  to  in of an  17 estimated mounted  accuracy of  on t h e N . I . O .  u s i n g an A u t o l a b ties  for  this  below t h i s  (inductively  level.  at  of  t i t r a t i o n method. approximately  this  time,  supplementing of  to  until  depths  of  quoted  uncertain-  was done a b o a r d  values Surface  temperature  information  ashore  a r e assumed to temperature  No o x y g e n  and  data,  formula.  was c o l l e c t e d f r o m  Cruise 75/20,  be  samples  and s a l i n i t y  (1901)  ship  June 13,  the  1975,  using  30 m (BT#13099) o r 60 m ( B T # 1 0 0 6 5 ) .  an I n t e r O c e a n  513  both temperature  CSTD p r o f i l i n g s y s t e m was  and s a l i n i t y d a t a  to  used,  a maximum  depth  30 m.  The  c u r r e n t m e t e r e m p l o y e d was a n A a n d e r a a  conductivity for  temperature  the survey  oxygen  Knudsen  was made  The  from a s u r f a c e b u c k e t .  u s i n g the  thermometers  2 8 . 0 ° / o o and ± 0 . 0 2 ° / o o  ±0.05 ml/1.  were computed  bathythermographs After  These  From t h e  of  Salinometer.  determination  the s u r f a c e .  Supplementary commencement  coupled)  a r e ± 0 . 0 0 3 ° / o o above  samples were t a k e n  were t a k e n  Keike reversing  S a l i n i t y determination  D i s s o l v e d oxygen  a c c u r a t e to w i t h i n  values  bottles.  instrument  by t h e W i n k l e r  salinity  ±0.02°C using Yoshino  this  instrument  hold value direction range  of  1.5  quote  in pressure. 0.1%  revolutions  generate  in direction for  of  an e s t i m a t e  range its of  extreme  speeds, ± 0 . 1 5 ° C in temperature,  No a c c u r a c y i s q u o t e d of  Manufacturers'  temperature, specifications  a c c u r a c i e s o f ± 1 cm/s i n s p e e d a b o v e  cm/s, ± 7 . 5 °  for mid-range  resolution of total  and p r e s s u r e s e n s o r s a t t a c h e d .  RCM4, w i t h  is stated.  Savonious average  for  This  Rotor over  speed.  the  Direction  thresh-  speeds, ±5° and ± 1 %  conductivity type  a  of meter  in  of  although  a  records  the  sample p e r i o d  to  i s sampled o n l y  at  18 one d i s c r e t e t i m e d u r i n g t h e s a m p l e i n t e r v a l . a s a m p l e p e r i o d o f 15 m i n u t e s was c h o s e n . consisted of a concrete anchor, itself, in the  The c u r r e n t m e t e r  mooring  an a c o u s t i c r e l e a s e p a c k a g e ,  and a s u b s u r f a c e f l o t a t i o n  n e a r l y 40 m o f w a t e r ,  For t h i s i n s t a l l a t i o n ,  pontoon.  the meter  With the system deployed  t h e m e t e r was s u s p e n d e d a p p r o x i m a t e l y  3 m from  bottom.  2.3  Secondary Data Sources  Meteorological sources.  and r u n o f f  A i r temperature  d a t a w e r e a c q u i r e d f r o m a number  and p r e c i p i t a t i o n d a t a from s t a t i o n s  i n g the s t u d y a r e a were t a k e n from the Monthly Observations (A.E.S.). Centre  i n Canada,  Runoff f i g u r e s  Outflow s t a t i s t i c s  Water D i s t r i c t .  f o r t h e F r a s e r and Seymour  o f Canada,  Inland Waters  from the C a p i l a n o r e s e r v o i r p l u s  from the C i t y  The d i f f e r e n c e i n t h e s e two f i g u r e s The B r i t i s h  into  consumption Vancouver  i s the net discharge  t h e two B u n t z e n  Authority  power  a n d s a l i n i t y d a t a a r e known  Though t h e s e d a t a w e r e n o t e x t e n s i v e l y e m p l o y e d i n t h e  present study,  t h e i r a v a i l a b i l i t y i s indicated f o r completeness.  Environment  Environment,  were  I n d i a n Arm.  secondary sources o f temperature  to e x i s t .  Weather  Directorate.  C o l u m b i a H y d r o a n d . Power  made a v a i l a b l e e s t i m a t e s o f d i s c h a r g e t h r o u g h  Pacific  Service,  Rivers  o f V a n c o u v e r w e r e p r o v i d e d by t h e G r e a t e r  from the Capilano R i v e r .  Two  Record o f M e t e o r o l o g i c a l  p u b l i s h e d by t h e A t m o s p h e r i c E n v i r o n m e n t  o b t a i n e d from the Water Survey  houses  surround-  D e t a i l e d w i n d d a t a w e r e made a v a i l a b l e by t h e P a c i f i c  of A.E.S.  figures  of  Institute  o f t h e Department  The  o f F i s h e r i e s and t h e  l o c a t e d on t h e N o r t h S h o r e b e t w e e n C y p r e s s a n d Godman  19 Creeks,  h a s i n t h e p a s t m a i n t a i n e d an i n t e r m i t t e n t p r o g r a m o f  and s a l i n i t y s a m p l i n g f o r exist  for  times concurrent with  systematic quality  The  Daily  m,  Narrows  Arch pool.  p l a c i n g the  at approximately  water at  further  approximately At  and t o t h e A q u a r i u m .  Inlet  intake, It  Data Reduction  Much o f  water  6.1  0800 h r s the t e m p e r a t u r e the  intake  through  the  sea f l o o r ,  is  the  depth a t  the  m i n the water  housing  column.  and s a l i n i t y o f  a pumping s t a t i o n a t  the  This  water  Lumberman's  system f o r approximately  Long t i m e - s e r i e s r e c o r d s  the Aquarium's  good  engineering  one  of  reports.  Techniques  t h e d a t a r e d u c t i o n and p l o t t i n g h a s b e e n a c c o m p l i s h e d  the use o f  Associated with  the  IBM 3 7 0 / 1 6 8 c o m p u t e r a n d C a l c o m p p l o t t e r  t h e use o f  do n o t a r i s e w i t h  the c o n v e n t i o n a l  s e c t i o n s through  system.  t h e s e m a c h i n e s a r e some d i f f i c u l t i e s hand p l o t t i n g o f  Indian  presented in Chapters  Arm and t h e  3 and 5 .  The  time-depth  format of  which  data.  A c o m p u t e r i z e d c o n t o u r i n g p r o g r a m was e m p l o y e d t o  later  a more  intake  system are recorded.  has been i n t h e  these data are a v a i l a b l e through  vertical  1977,  records  Studies.  365 m n o r t h w e s t o f  i n t a k e a t a depth of  h o u r when t h e m e a s u r e m e n t s a r e made.  with  Some d a t a  Since early  3 m above  l o w e s t low t i d e ,  the Aquarium end o f  has p a s s e d f r o m t h e  2.4  Burrard  intake housing, which extends  in First  Lumberman's 9.1  survey.  system.  Vancouver P u b l i c Aquarium a l s o m a i n t a i n s a sea water  system. located  this  intake  s a m p l i n g p r o g r a m has b e e n u n d e r t a k e n and s h o u l d p r o v i d e  t i m e - s e r i e s data f o r  The  is  i t s sea w a t e r  temperature  prepare  the  sections  these  programs  Arch,  20 required that distributed series  of  developed data,  two  property  i n the  regularly  spaced depths.  by R a t t r a y  (1962),  to  c a l c u l a t e values  estimates  p a r a b o l i c Lagrange (one above  interpolation  the  below  a n d two b e l o w ,  depth).  (1968)  three  demonstrated  procedure  greatest  changes  depth  the  of  points  four)  near-surface  interpolate  bottle.  Below t h i s  in  the form of  salinity  versus  strong  sample  to j u s t i f y  depth  of  the  analogue depth.  In  use o f  unmodified  uses t h r e e  p r o f i l e s of  sample. averaging  sample the  by R a t t r a y and  amplified  this  the  improve  still  the  demands  present data,  between Thus,  at  least  the  t h e s u r f a c e and insufficient  this modification  for  the  data the  a s i m p l e l i n e a r scheme was  Rattray  depth of  the  scheme was  Output from the temperature,  first  employed.  r e d u c t i o n which r e q u i r e d computer  CSTD d a t a .  The  and  a n d one b e l o w  gradient  (2 o r 5 m ) . the  at  bottle  by e v a l u a t i n g  t h e s u r f a c e and t h e  the  data  oceanographic  first  and R o s s t o  Consequently,  between  A s e c o n d phase o f was p r e p a r a t i o n  the  a  gradient.  by R e i n i g e r  interpolations.  used to  scalar properties  o r two a b o v e  sample p o i n t s .  bottle  are a v a i l a b l e  the  value  c o n s i s t e n t l y are observed  first  use w i t h  depth of  at  routine  for  each o f which  strong  in regions of  (preferably  the  irregularly  values  i n d i c a t e d the a c c e p t a b i l i t y of  p r o c e d u r e away f r o m r e g i o n s o f  Rattray  generate  E r r o r a n a l y s i s performed  by R e i n i g e r and R o s s  The m e t h o d  of  interpolated  Polynomials,  to  were  A basic interpolation  specifically  i n t e r p o l a t i o n depths  routine  points  d a t a w h i c h , when c o l l e c t e d ,  v e r t i c a l , be i n t e r p o l a t e d  was e m p l o y e d  desired This  the  InterOcean  conductivity  salinity is calculated internally  assistance CSTD i s and from  21 measured c o n d u c t i v i t y a second t h e r m i s t o r  and f r o m a c o m p e n s a t i n g  (additional  temperature  to the primary  measured by  temperature  sensing  thermistor).  As an i n i t i a l was made b e t w e e n profile  step  i n a n a l y s i s o f t h e CSTD r e c o r d s ,  the i n t e r n a l l y c a l c u l a t e d s a l i n i t y p r o f i l e ,  calculated externally  and t h e s a l i n i t y d e t e r m i n e d minutes  prior  calculated externally.  typically within  Subsequent (personal  determination.  6 m depth)  is  Gain  on t h e i n s t r u m e n t  employs  adjustments such t h a t  by J .  than values  t o be  Stronach cumulatively  up t o 1 . 5 ° / o o .  two s e t s o f c i r c u i t r y f o r than  t h e computed this  Secondly,  i n the t h e r m i s t o r  2 0 ° / o o and t h e  value  instrument  (typically  l a g the true an o v e r a l l  to  about  s a l i n i t y by  time  used t o measure  salinity calculation.  appropriate  other  s a l i n i t i e s do n o t  being c a l c u l a t e d using the c o r r e c t  using a temperature  salinity  during the period of  For s a l i n i t i e s below  f o r the i n t e r n a l  i s thus  15  internal  the e x t e r n a l  s a m p l e s was o b s e r v e d  the i n t e r n a l l y c a l c u l a t e d values  amounts,  temperature  but  Agreement between  i d e n t i f i e d two f a c t o r s w h i c h  The i n s t r u m e n t  thought to e x i s t  salinity  as c a l c u l a t e d by t h e  cause o f the i n a c c u r a c y i n the i n t e r n a l  s u r v e y were  match a t 2 0 ° / o o .  varying  Salinity  from b o t t l e  work p e r f o r m e d  values.  use f o r t h i s  temperature,  samples taken a p p r o x i m a t e l y  c a l c u l a t i o n ; one f o r s a l i n i t i e s l e s s  higher  and p r i m a r y  0.5°/oo.  communication)  are the probable  for  from b o t t l e  the s a l i n i t y  t o be c o n s i s t e n t l y l o w e r by 2 t o 3 ° / o o  and t h e s a l i n i t i e s m e a s u r e d  salinity  using conductivity  t o t h e CSTD c a s t .  c i r c u i t r y was o b s e r v e d salinity  a comparison  lag effect  compensating  A t any g i v e n  depth,  conductivity,  to a l e s s e r depth.  Since  temperature  22 in  general  instrument which  depth  was u s e d ) ,  resultant effect  i s too  explanation salinity. and t o  for It  of  This  the  The  superposition of  the observed  was t h u s  an e x t e r n a l  conductivity  d a t a was e m p l o y e d  the  bottle #41,  profiles.  The  data  two e f f e c t s  than  100  the  Columbia.  an  recorded s a l i n i t y the  data,  recorded  digitization  of  samples proved profiles.  This  all  these  digitized  reconstruct  calculated  t o be  consistently  set of  salinity  time-scale time-depth  sections  3.  Data  Base to  have b e e n p u b l i s h e d  the  salinity  internally calculated  s a l i n i t i e s thus  short  indicate briefly  set compiled during t h i s  of  this  i s s e e n as  i t was p o s s i b l e t o  of  from b o t t l e  i s now p r e s e n t e d  stations  calculate a  By i n t e r p o l a t i n g  depths,  agreement  in generating  Resultant  1975,  British  of  when  temperature.  f o r more  i n Chapter  A summary of  and  and c o n d u c t i v i t y  than 0 . 5 ° / o o  2.5  these  disregard a l l  to a c o n s i s t e n t s e r i e s of  discussed  i s to  t h e months  s a l i n i t y c a l c u l a t i o n from  s a l i n i t i e s determined  better  behaviour  chosen to  salinity profiles.  with  (especially during  process n e c e s s i t a t e d the mechanical  temperature traces  low.  perform  profiles  the  decreases with  Institute All  of  study.  All  the  data  i n Data Reports  Oceanography o f  secondary data  the  total  collected  #37,  1974  University  are maintained  scope at  and of  on f i l e a t  that  Institute.  During  the  were o c c u p i e d . at  a series of  18-month f i e l d p r o g r a m , At  430 o f  these,  d i s c r e t e depths  some 560 o c e a n o g r a p h i c  temperature  while at  and s a l i n i t y were  approximately  200,  the  stations determined concen-  tration  o f d i s s o l v e d oxygen  t h o s e 430 s t a t i o n s were CSTD c a s t s . locations. Arm s i l l the  supplemented w i t h  In a d d i t i o n , A 93-day  was d e t e r m i n e d  record of near-bottom  location.  and d i s c u s s i o n o f t h i s  either  Virtually  data  currents over  temperature  the  or  times and Indian  and s a l i n i t y r e c o r d s  The f o l l o w i n g c h a p t e r s base.  a l l of  bathythermograph  130 CSTD c a s t s w e r e made a t o t h e r  was c o l l e c t e d , a l o n g w i t h  c u r r e n t meter  as w e l l .  are a  at  presentation  24 CHAPTER 3 SHORT PERIOD TIDAL FLUCTUATIONS 3.1  General  The  general  examined in  this  nature  of  of tides  by b o t h W a l d i c h u k  heights  and d i u r n a l  i n the Burrard  (1964)  and T a b a t a  constituents.  o f s u c c e s s i v e lows and s u c c e s s i v e h i g h s  ranges  Inlet  are about  are e f f e c t i v e l y  In  contrast  25 m i n u t e effect  i s most  Burrard at  First  from  Inlet,  extrema  probably  Turbulent  mixing  and B u r n ' s  on b o t h  associated with  Mean t i d a l a r e 4 . 8 m.  tidal  there  extrema  i s an  and a t P o r t  These  Point.  occur  Moody.  shallowness  Also  times  f l o o d and ebb t h r o u g h tidal  the d i s t r i b u t i o n of s c a l a r  at  l e a s t a t those  the narrows  (Tabata,  of  channels  currents which at  these strong  This  resultant  a p r i n c i p a l mechanism a f f e c t i n g nearest  ranges  approximately  is  stations  as a  inequality  due t o t h e n a r r o w  constrictions are t i d a l  r e a c h maximum s p e e d s n e a r 6 k n o t s narrows.  Atkinson  some e f f e c t  Second Narrows,  these physical  where  a consequence o f the r e l a t i v e  a n d may r e f l e c t  Narrows,  ranges  and h e a d ,  at Point  This  in  the i n l e t .  t o t h e c a s e o f deep f j o r d s  l a g between  both  inequality  i s observed  position.  3 m, w h i l e e x t r e m e  a t b o t h mouth  tides  i t s maximum d e c l i n a t i o n a n d i s  t h e same t h r o u g h o u t  almost simultaneously  In summary,  o f t h e moon.  a s t h e moon p a s s e s t h e e q u a t o r i a l  in Burrard  (1971).  s y s t e m has been  A large diurnal  m o s t p r o n o u n c e d when t h e moon a t t a i n s  minimized  Inlet  implying the presence of  consequence o f the d e c l i n a t i o n a l e f f e c t is  DISTRIBUTIONS  Tides  r e g i o n a r e d e s c r i b e d as m i x e d ,  semi-diurnal the  Description  IN PROPERTY  1971).  the  currents properties  25 3.2  Reference Tidal  Prior  Curves  t o commencing a t r e a t m e n t  t o d e s c r i b e t h e way i n w h i c h t i d a l present program. of  the t y p i c a l  Any  actual  of actual  data  tidal  curves f o r Burrard  s i t u a t i o n observed  c a n be a p p r o x i m a t e d  tidal Inlet,  in Burrard  by one o f t h e s e c u r v e s . into  12 e q u a l  i t i s necessary  have b e e n d o c u m e n t e d f o r t h e  Two e m p i r i c a l , 2 5 - h o u r  tidal  results,  curves,  representative  are presented Inlet  in Figure  during the  Each c u r v e  as shown,  each b o t t l e  c a s t o r CSTD c a s t h a s b e e n a s s o c i a t e d t h e b i n number  Where  pertinent  quoted w i t h  further  figures  1 hour f o r any g i v e n  Fluctuations  at Periods  temperature 27,  3.7 of  short  3.11)  3.1  to determine  fluctuations  been  c a n t h u s be  t h e phase o f t h e  on C r u i s e 7 5 / 2 8 ,  i n t h e week  11,  11-5,  of  sections  11-8,  l o c a t i o n s are i d e n t i f i e d i n Figure  i s now u n d e r t a k e n  period tidal  have  cast.  a n d s a l i n i t y f o r s t a t i o n s Van l l r l ,  of these sections (presented  through  Figure  have a l l o w e d t h e p r e p a r a t i o n o f t i m e - d e p t h  34 and I n d 0 ( s t a t i o n  analysis  t h e s e b i n numbers  L e s s Than 12 H o u r s  D a t a t a k e n d u r i n g t h e CSTD s u r v e y August 2 5 , 1975,  With  c o n d i t i o n a t the time of the c a s t .  the g r a p h i c a l l y presented d a t a .  t o w i t h i n about  3.3  bins of length 2.08 hours.  i n the f o l l o w i n g c h a p t e r s ,  used i n c o n j u n c t i o n w i t h tide  tidal  survey  has been  subdivided,  representative of the actual  17,  of 24,  1.1(b)).  as F i g u r e s  3 . 2 through  3 . 5 and  to determine  the t y p i c a l  magnitudes  i n the d i s t r i b u t i o n s of  temperature  and s a l i n i t y .  To i n t e r p r e t some s t a t e m e n t pairs  of  correctly the features instrument  3.1.  o b s e r v e d on t h e s e s e c t i o n s ,  p r e c i s i o n m u s t be made.  o f CSTD p r o f i l e s t a k e n a t f i x e d  sites  less  than  Inspection 3 minutes  of apart,  An  26 has p r o v i d e d vertical  an e s t i m a t e  structure.  or conductivity imately sections for  a i m  of  Thus,  The  various  station.  The  3.3.1  Tidal top  axis of  CSTD c a s t .  The  tidal  bin  1 -  to  time-depth  (Figures  3.2  through  information  i n c l u d e the  at  1005  at station  Van  Over t h i s  h PST, 11-1.  at  11,  time-depth  the order of  of  1 m  instrument vertical  be r e a l  11-5,  manifestations  geographically  Van  by  11-8  i s presented along  point  represents  flood  period of  portion  of  flood  (bins  the  only evident  a specific  axis.  22  i s seen  from  ebb f r o m l o w h i g h tidal  series  minimal  s a l i n i t y and t e m p e r a t u r e . 19),  measureable of  8 m,  to  the  to  water  c y c l e , the  mouth show r a t h e r  18 a n d  to a depth  the  from low low water  a full  harbour  the  bottom  18 t h r o u g h  stages of  the  the  approx-  s e c t i o n s a r e now d i s c u s s e d .  Van  sections  d i s t r i b u t i o n of  Here,  of  i s given along the  final  over  3.5)  these  by t h e f u l l  s e c t i o n s from s t a t i o n s  water  for  Van  c y c l e r e p r e s e n t e d by b i n s  stages of  up t o  temperature  phenomena.  Each i d e n t i f i e d  of  latter  terms o f  sections, only  each group  11-1,  h i g h low w a t e r .  the  of  Van  vertical  In  considered to  Stations  to  i n the  fluctuate  s e c t i o n s have been g r o u p e d  basic features  followed  to  excursions  flow or wind mixing  Time i n f o r m a t i o n  low high water  changes  2 m are  reproduce  at which a given  l i n e may be an a r t i f a c t  each f i g u r e .  tidal  Figure 3.1  vertical  c a p a b i l i t y to  casts.  in considering these  exceeding  short-term  the depth  on r e p e t i t i v e  a p a r t i c u l a r contour  fluctuations  instrument's  i s r e c o r d e d may be e x p e c t e d  implies that  performance.  the  On a v e r a g e ,  interval  this  of  time of  change t a k e s  During high  place  a minor deepening of  the  27 contours  of  both  introduction  As t h e the  top  of  2 to  tidal  s l i g h t l y warmer,  ebb d e v e l o p s ,  directional the  s a l i n i t y and t e m p e r a t u r e  phase  l°/oo of the  the  time  corresponding  Below in the  structure are  at  moderate base of  station  Van  thermocline this  11-1  observation Even a t  depths  i n t r u s i o n of Approximately  i n the  likely  greater  than  of  km t o  the  of warmer,  the  less  Although  flowing  3.5)  of  the  3 to  there  the surface.  s a l i n e water  no  section,  surface  layer,  indicate that harbour  4 hours  the  mouth.  are  Typical  seen t o  An e x t r e m e  at  be  11-5.  of  the  increases in surface s a l i n i t y  and  4 m.  there  all  four  are obvious stations.  To  these  the  shows a s h a r p  E x t e n d i n g downward  property  distributions  the  only  near  station  the  Van  11  changes near  halocline to  over  motion  observed  short-term  north,  in which there  implying only minimal  south,  presumed  differences  While  stations,  section.  is a layer  15 m,  At  temperature.  layer  at  about  change  s t a t i o n Van  is a relaxation  Point  the  i s no  evidence  the  hour  change  time of  too  and  15 m f r o m  at  in  explicit  a single transverse  i s observed  s l i g h t l y more d e n s e w a t e r s 0.8  near  in temperature.  (Figure 3.2)  pycnocline region  period,  width  transverse  at 3 to  s i g n i f i c a n t change  from  the d i f f e r e n t  small  seen t o v a r y a l o n g the  flow  through  22)  in surface  shallow surface  in structure  Atkinson,  of  decreases  property  changes  0.5°C  by  s a l i n e water  stations.  a period  as evidenced  this  3.2  (bin  i n d i c a t i v e of  be a w e s t w a r d  3°/oo in s a l i n i t y  h i g h low water  flow,  all  entire  s u r f a c e over  than  of  westward  are  the  i n s a l i n i t y and a b o u t  greater  to  (Figures  spans e f f e c t i v e l y  changes a t  at  is available  implies this  and t h e d i s t r i b u t i o n s flow  an a p p a r e n t  3 m i s suggested information  less  is  6  this is  low  (Figure 3.3)  level.  an tide. shows  28  a definite Although 1.5°C  h a l o c l i n e and m o d e r a t e  absolute d i f f e r e n c e s of  i n temperature  Van 11-1, at  thermocline approximately  are s i m i l a r to  the v e r t i c a l  gradients  t h i s s t a t i o n at depths  a t Van 11  greater  distributions are,considered  the  l i k e l y i m p l i c a t i o n of minimal motion.  in  presence of  the  w a t e r s were in density evidence  that these  near  18  and 3.5)  the s o u t h ,  i n s i g n i f i c a n t , with  in  again  change c o u l d a l s o  result  if  the  previously  at  properties  of  the  resident waters.  s l a c k water  stations  Van 11-5  show a c o n s i d e r a b l y w e a k e r  stations.  deepening  of  stations  the  a t Van  11-1  advected  The  increase  i s not  Van 11-5  exceeding  behaviour less  changes a t  Generally,  10  and 11-8. m, where but  in  the s u r f a c e ,  previously  to  i s noted  the e n t i r e  upper  from the  ebb,  t h e 2 9 ° / o o i s o h a l i n e and t h e nearer  to  i n d i c a t i v e of  a l l depths.  a probable  resident  behaviour  the  a  the  is  two  m. more  observed at  10°C  isotherm well.  marginally  the e a r l i e r  observed  i s the advection harbour  10  gradual  s u r f a c e as  a flow of  As w i t h  explanation  the east of  the  3.4  gradients  These changes are most marked  i s most p r o b a b l y at  (Figures  s a l i n i t y and t e m p e r a t u r e  are evidenced  s a l i n e water  11-8  d i s t r i b u t e d through  throughout  of both  and Van  pycnocline, with vertical  i n temporal  contours  are representative,  waters  changes  periods of marginal  m observed  northerly  warmer,  temporal  Again  be  those of  A significant difference  This  at  p o s s i b i l i t y i s to  a t any p a r t i c u l a r t i m e b e i n g e v e n l y  depths  and  here.  Further to  at  3 m,  5 m.  The  s i g n i f i c a n t motion,  s i m i l a r to  7°/oo in s a l i n i t y  are o b v i o u s l y weaker.  than about  property  however,  r e g i o n from 2 to  those across the p y c n o c l i n e  the  noted,  i n the  entrance.  of  This in  the  same s i t u a t i o n  outer  harbour  i s i l l u s t r a t e d by t h e  on J u l y  These  p r o f i l e s are presented  south  transverse  portion  of  the outer  mouth  transverse  inset  tidal  of  s e c t i o n at  the top  north  small.  the  is  t h e upward  hour  later.  surface  turning 1330  summary layer  then,  is  Along the  northern  i n the  each p a i r except Van 11-1  more s a l i n e w a t e r south,  from  the  the  of  and 1 4 - 2 )  in Figures  interest at  of  the  station  contours  h PST,  and t h e  3.4  11-5  subsequent  central harbour  As s e e n f r o m  the  Consideration  f r e s h e r water  at  tide,  side there  below t h i s i s noted  extent  appears  layer. near  the  to  the  to  (shown  in Figure  s h a l l o w e r than downward  7 m  one  is  cool s a l i n e  have a  about  turning  this  3.4)  water.  3 m thick westward  transverse  section.  if  any  tidal  N e a r 18 m a p o s s i b l e f l o w o f  cooler,  shore.  further  Near m i d - c h a n n e l  ebb f l o w e x t e n d i n g  to  observed.  Such b e h a v i o u r  i s consistent with  the  relatively  narrow  jet  are  3.5.  be o n l y m i n i m a l  a potential  surface t i d a l  and  an a p p r o x i m a t e l y  of  the  shallowest 3 m along  elsewhere,  l o c a l i z e d i n t r u s i o n of  on a n e b b i n g  north-  where t h e d i f f e r e n c e s  at depths  i s observed  taken  3.6.  s u c h a d i s t r i b u t i o n w o u l d be e x p e c t e d  f l o w a c r o s s the f u l l  immediately  the  123°15.8'W.  i d e n t i f i e d and i s c o n s i d e r e d t o  of  to  longitude  of  be a s m a l l  component  flow  counterpart  As no s u c h f e a t u r e  considered to  In  and i t s  e a r l i e r noted  feature  at approximately  1 2 3 ° 1 3 . 3 ' W through  warmer,  (stations  behaviour  A final  in Figure  one f r o m a s t a t i o n on t h e  shows c o m p a r a t i v e l y  On a n e b b i n g t i d e  yield  profiles  a p e r i o d o f ebb i s a g a i n r e p r e s e n t e d .  few m e t r e s  shore  and p r e s e n t e d  in pairs,  harbour,  more e a s t e r l y s t a t i o n the  1975,  longitude  section at  curve,  25,  s e r i e s of  at  and  l e a s t 20 m d e p t h  phenomenon  of  w h i c h i s known t o d e v e l o p  is  a along  the  30 north  s h o r e on t h e e b b .  be v e r y  s h a l l o w as w e l l  broader,  deeper,  southern  portions  of  water  to  Two stations in  the  by b i n s to  Van  Van 24 to  The  suggest that i s to  The  features  of  (Figures  followed  time of  the  the  3.7  (see 3.7  such s t r u c t u r e ranges of  constantly  i s never w e l l temperature  passes through water  the  from  high  was 1355  that  defined  observed  following Tide  at  inside.  l e a s t at depths  have been m i x e d , Assuming  changes  17,  time,  outside  the  while  narrows  B o t h phenomena  Tables,  less  than  of  tidal  are  p l a c e as  sill  water  5,  1975)  of  1.25  First  Narrows  i s 3.0  First to  be speed  m/sec i t  km w i t h i n  km and t h a t  to  at  through  currents  a water p a r t i c l e exceed 8 . 5  As t h e d i s t a n c e f r o m Van 24 t o  depth  and u s i n g an e s t i m a t e d maximum Volume  a  Secondly,  on p a s s i n g e i t h e r  the development  slack water,  displacements of  PST.  A s i m p l e c a l c u l a t i o n c a n be u n d e r t a k e n  at  and C u r r e n t  h  these  s t a t i o n Van  s t a t i o n Van 2 4 .  from  low  a t any g i v e n  considerable mixing which takes  narrows.  o r Second Narrows.  (Canadian  surface at  and s a l i n i t y o b s e r v e d  from the  Van 24 m u s t r e c e n t l y  sinusoidal  the  that  First  i s an e b b  d i s t r i b u t i o n s at  i s noted  exceed the ranges observed  resultant mainly  show t h a t  6 m of  it  and  3.1)  and 3 . 8  by a f l o o d  the  spanning  are b r i e f l y described p r i o r to c o n s i d e r i n g temporal Firstly,  must  3.8)  Figure  h i g h low water  property  central  and  stations  phase  13 on F i g u r e s  this flow  be c o n t r a s t e d w i t h  the p a i r of tidal  high low w a t e r ,  high high water.  general  17,  19 t h r o u g h  these d i s t r i b u t i o n s .  found  mouth.  1.1(b)).  pycnocline exists within  the  This  harbour  i s now g i v e n  (see F i g u r e  low h i g h w a t e r  as n a r r o w .  Stations  Consideration  represented  present data  ebb f l o w w h i c h i s i n f e r r e d t h r o u g h  3.3.2  Narrows  The  to  3  is hours.  31 Second Narrows i s 5 . 0 of waters  only  of  Figures  flood  through  temporal 3.7  number o f  to  flood  properties  of  17,  1355  the ebb, h PST.  the f l o o d at  f r e s h e r water freshening  top  of  1400  Thus,  evidence.  property  is values  observed  3 m of  in a  flow.  the water  a t Van 17  e a r l i e r observed  found west  hours  exhibits  approximately  h PST  for  about  at  Van  the  a t Van 17  i n the  3 m and 6 m  c o u l d p o s s i b l y be e x p l a i n e d  However,  following  0930 h PST  of  Of  particular interest  vertical  f l u c t u a t i o n observed  i n the  downward  layer  the  the  i s not  harbour, layer  tide.  Water  flow of  warmer,  and  directly  Such  mixing of  behaviour surface  below 6 m i s the  having  The  commencement  large  i n t h e 2 8 ° / o o i s o h a l i n e and i n t h e  h PST.  turn  having  outer  the warming  a n ebb f l o w .  by e x t e n s i v e  waters.  of  is a  the expected  same  The  f r e s h e r water  surface.  effects  the  17  3 hours f o l l o w i n g t h e  c a n be a s c r i b e d t o  of  a t Van 2 4 .  salinities  o f Van 17  ebb-  column  W i t h i n two  as r e a d i l y d e s c r i b e d i n terms of  contours  1400  tidal  in  Throughout the f u l l  i n f l u e n c e of warmer,  the expected  centred at  illustrated  but r e v e r s e s w i t h i n a few m i n u t e s  The  at  2 to  and h i g h e r  L y i n g between  as n o t e d  consistent with  in  place.  by c o n s i d e r i n g c h a n g e s  surface water  s u c h as a r e n o r m a l l y  deepening  isotherm,  the  surface water  i n which changes are not  of  take  as homogeneity  distributions  l a y e r s at each s t a t i o n .  0820 h PST,  i s soon observed.  gradual  in property  c o o l e r temperatures  through at  in fact  reducing the range of  b a s i c a l l y non-mixed  as those  toward  thus  s t a t i o n Van  t o ebb a t  properties  does  are modified  are best explained  individual  continues  narrows  mixing  narrows.  changes  show e v i d e n c e o f  trend  mixing,  and 3 . 8  cycle at  the turn  the  suggested  r e l a t i v e l y weak s t r a t i f i c a t i o n i s e v e r  i n s i d e the  The  c a n be a s s u m e d t h a t t h e  s a l i n i t y and t e m p e r a t u r e  approached observed  it  by p a s s a g e t h r o u g h  a t Van 2 4 , Extremes  km,  such p r o p e r t i e s  is  10.5°C seen  32 from Figure structure this of  3 . 8 to  of  reside at  15 t o  18 m d e p t h  t h e c o n t o u r s a t Van 17  i n s i d e the narrows.  i n d i c a t e s that water  d e p t h has moved on t h e ebb t h r o u g h  from at  least  the narrows, w i t h a s i l l  depth  14 m, and i s now f o u n d a t d e p t h s a s s h a l l o w a s 5 m.  could  in fact  The  This  water  h a v e o r i g i n a t e d b e l o w 18 m i n s i d e t h e n a r r o w s ,  and  have  been m o d i f i e d t h r o u g h m i x i n g t o a c q u i r e i t s p r o p e r t i e s a s o b s e r v e d Van 17. Van 2 4 ,  It  is likely  that  to flow through  the ebb.  the c o n t r i b u t i o n of  the narrows,  minimal  h PST.  At  changes are observed  isotherm. by t i d a l  1145  It  h PST)  water  depths greater  than  about  t h i s water as w a t e r  the present data that to  the upper  10 t o  a single tidal  significant tidal  12 m o f  the water  A g a i n a t s t a t i o n Van 24  ebb,  having these properties  cycle.  It  the behaviour of  from t h a t  of  not  a p p e a r a t Van 24 a s h i g h e r s a l i n i t i e s  temperatures.  As t h e f l o o d d e v e l o p s ,  temperatures.  In  change i s observed  the range of  the  in the property  10 m a t  upper  waters. of  and s l i g h t l y  near-surface waters  lower s a l i n i t i e s  3 to  from  are confined  underlying  Second Narrows  to  is  thus appears  e f f e c t s a t Van 17  (Figure 3.8)  cause a r e v e r s a l  10°C  is significantly influenced  On t h e e b b , w e s t w a r d f l o w i n g s u r f a c e w a t e r s f r o m t h e v i c i n i t y  Narrows  17,  column.  2 t o 3 m i s o b s e r v e d t o be d i f f e r e n t  First  at  12 m a t Van  f o u n d o n l y b e l o w a b o u t 25 m i n t h e v i c i n i t y o f Van 24 and i s e x p e c t e d t o be e x c h a n g e d o v e r  of  a well  i n t h e 2 9 ° / o o i s o h a l i n e and i n t h e  from the narrows,  from  from  h a s been e s t a b l i s h e d n e a r f u l l  i s not expected that  outflow  1100  i s e n t r a i n e d i n t o the f l o w u n t i l  developed flow of deeper water approximately  these deeper waters  i s minimal i n the e a r l y stages  A s t h e ebb p r o g r e s s e s ( s a y a f t e r  g r e a t e r and g r e a t e r d e p t h s  at  and  passing  through  higher  t h i s s t a t i o n , very  d i s t r i b u t i o n s over a  lower  10-hour  little  33 period.  At  depths  the contours  greater  i s observed  comparable upturning evidence of  of  than  10 m a g r a d u a l ,  through  the period of ebb,  on t h e e b b ,  and o f  which are r e s i d e n t outside F i r s t flood.  These must both  through  the Narrows,  properties  of  the mid-depth  it  that  of  at  these depths during  l a y e r are a c t u a l l y determined changed d u r i n g the  f l u c t u a t i o n s due t o  tidal  near  the  tidal  10 m a t Van  3.3.3 Sections t h e mouth o f considered  by m i x i n g ,  cycle.  In  general,  flow are observable to  Van 2 7 ,  Van 3 4 ,  Ind  0 (Figures  f r o m two s t a t i o n s s p a n n i n g S e c o n d N a r r o w s I n d i a n Arm a r e now d i s c u s s e d .  and t h e s u b s e q u e n t  of  at limit  an e b b i n g t i d e ,  low a t  1430  h PST.  Again,  with  the  the  high at  3.9,  3.10,  At  and on t o  Van 2 7 ,  (Figure 3 . 9 ) . later  Indian  time  0905 h  PST, trend Second  Arm.  a t Van 2 7 ,  that  shown  o b s e r v e d one  day  be s l i g h t l y more d e n s e w h i l e  e x c e e d i n g 12 m a r e m a r g i n a l l y l e s s  the changes i n the p r o p e r t y  a t Van 24 i s  surface waters  t h a n t h o s e a t Van 24 a r e s e e n t o  at depths  at  interval  The e a r l i e r i d e n t i f i e d  a d i s t r i b u t i o n s i m i l a r to However,  3.11)  and a t h i r d  toward weaker s t r a t i f i c a t i o n p e r s i s t s i n p a s s i n g eastward through Narrows  the  17.  Stations  i s that  flow  Thus,  20 m d e p t h a t Van 24 i n c o n t r a s t t o t h e e a r l i e r i d e n t i f i e d  about  is  c o l d e r more s a l i n e w a t e r s  to produce the observed d i s t r i b u t i o n s .  they are l i t t l e  least  from  be m i x e d w i t h s h a l l o w w a t e r s d u r i n g t h e i r  even though i s noted  Narrows  Such b e h a v i o u r  f l o w i n g westward  i n f l o w of  of  f o l l o w e d by a  t h e c o n t o u r s on t h e f l o o d .  s l i g h t l y warmer f r e s h e r w a t e r s  Second Narrows  uniform deepening  d i s t r i b u t i o n at  dense. this  On an e b b i n g  s i t e are the  waters  tide,  reverse  34 of  those observed  the  a t Van 2 4 .  c o n t o u r s was n o t e d ,  trend,  While e a r l i e r , a gradual  in this  instance there  i m p l y i n g a s o u r c e o f c o o l e r , more  profiles  not here presented determines  26.8°/oo  and t e m p e r a t u r e s  depth  a t Van 3 4 .  cannot 6 m.  less  than  Thus, waters  A potential  explanation  Canadian Hydrographic Vancouver  Harbour,  persistent ebbing  eddies  tide,  develop  s a l i n e water.  that  through  at depths  c a n be d e r i v e d  1973".  Studies  i n the central  a pronounced  of Tidal  cyclonic (anticlockwise)  eddy  v e r t i c a l l y t o 20 m d e p t h ,  s a l i n e waters  from f u r t h e r  to the west,  5 m a r e so s m a l l  that  no d e f i n i t e  as t o t h e s o u r c e o f t h e s e w a t e r s , flow  through  structure  Second Narrows  i n the central  identified  the  salinity section  associated with this  station.  exceeding  whether  or whether  s t a g e s o f an i s know  to  Such a  could provide  i n t h e upper  be r e s u l t a n t  more  upward  can r e a l i s t i c a l l y  they  they  identified  explain the  Changes  Charts,  3 to  be made  from ebb  be a s s o c i a t e d w i t h  an eddy  harbour.  Through Second Narrows, are  and t h u s  statement  about  Current  to the south of mid-channel.  i d e n t i f i e d a t Van 2 7 .  Narrows  than  have  On t h e l a t t e r  i t to extend  of contours  of  from c o n s i d e r a t i o n of the  were  turning  of  a t any  Second  greater  of surface currents  harbour.  upwards  i n excess  1 2 . 0 ° C a r e n o t t o be f o u n d  behaviour  of  Inspection  salinities  Service publication "Atlas  near Second Narrows,  feature,  exists a definite  p a s s i n g westward  account f o r the observed  downturning  at station  i n the temperature  variations  s e c t i o n , and t o a l e s s e r e x t e n t  (Figure 3.10).  the turbulent  Van 3 4 , i r r e g u l a r  Such v a r i a b i l i t y  f l o w so f r e q u e n t l y  By t h e p r e s e n c e o f w a r m e r  experienced  f r e s h e r water  10 m , a n d b y t h e l a c k o f v e r t i c a l  i s no  structure,  at  in  doubt in occupying  depths  i t c a n be  35 assumed t h a t Narrows of  the  the e f f e c t s  m u s t be l a r g e . 12°  the ebbing  Also of  isotherm after  at  Ind  than  unchanged  through  the  3.3.4 On A u g u s t  i.e.  tidal  most o f  1975  salinity  the  Van  i s noted a t  11  (Figures  ebb.  f l o w westward  on  and  temperatures  take  had r e t u r n e d  may be e v i d e n c e o f  3,  and  however,  remains  3.13) 1975  a s e r i e s of  CSTD  Howe Sound  through  low  tide  and t h e commencement from these c a s t s  i n d i c a t i o n of  few m e t r e s .  At  3 ° / o o and t e m p e r a t u r e  near  the t i d e ,  i s the  top  place in less  to  On  4 hours  2 hours f o l l o w i n g  s e c t i o n s prepared  1 hour t h e d i s t u r b a n c e  flooding condition of  be  of are  3.13.  i n c r e a s e s i n excess of  approximately  surface,  approximately  high high water  a d e n s e w a t e r mass i n t h e  to  the  properties  and  c y c l e from about  through  3.12  over  s i g n i f i c a n c e i n each i n s t a n c e ,  2 ° C were o b s e r v e d  are seen to  i n t e r v a l s were t a k e n a t s t a t i o n Van 11.  Time-depth  as F i g u r e s  3.12  and a g a i n on S e p t e m b e r  tidal  the f l o o d  the subsequent  passage of  deepening  a s l i g h t decrease i n s a l i n i t y  o c c a s i o n s , the sampling extended  Of  observed  the  ebb.  15 m i n u t e  same p h a s e o f  effects  2 m the d i s t r i b u t i o n of  Station 19,  spaced at  presented  from o u t s i d e  a s warm w a t e r s  increase i n temperature  greater  the  0930 h PST,  Near low w a t e r ,  at depths  both  entering  s i g n i f i c a n c e i s the  0 ( F i g u r e 3.11)  insignificant.  corresponding  casts  i n water  tide.  Finally, almost  of mixing  it  than  half  the  3 m depth,  decreases  an h o u r .  earlier values.  i s expected  surface water  that  such  near  Within  had p a s s e d a n d s a l i n i t i e s  their  brief  Given  and the  observations  being advected  around  Point  36 Atkinson.  No a c t u a l  course of  this  3.4  observations  tidal  flow  depth  at a l l  throughout  Burrard  stations.  have  depths  while off  this  the hypothesis.  At  Burnaby  tidal Shoal  Station  Van 27  the ebb,  24,  while  a t Van 3 4 .  it  i.e.  small.  seasonal  fluctuations  It  will  chapter.  On t h i s b a s i s i t w i l l  at depths  greater  temperature phase o f  further  study  basic nature hereafter  3 m,  than are the  tide  at  the  First to  10 m  an  at  eddy  t h e mouth o f  Indian  insignificant.  of  tidal  the of  influences  present  these  analysis  are  5)  seasonal d i s t r i b u t i o n s of  that  of  changes d e s c r i b e d i n  be a s s u m e d i n s u b s e q u e n t  this  chapters  salinity  that  and  p a r t i c u l a r concern  time the d i s t r i b u t i o n s were  has  influences,  (Chapter  properties  c a n be d i s c u s s e d and c o m p a r e d w i t h o u t the  only  at  irregular  be shown  i n the d i s t r i b u t i o n s of  c o n s i d e r a b l y g r e a t e r magnitude  than  at  i s suggested that  i l l u s t r a t e the  are  Finally  flow  i d e n t i f i e d to  evidence of  f l u c t u a t i o n s were  been s u f f i c i e n t t o they  to extend  changes were  3 m  differences  outside  i n s i d e Second Narrows  T h e r e r e m a i n s much s c o p e f o r however,  small  of  various  evidence of  Immediately  showed p o t e n t i a l  s a l i n i t y and t e m p e r a t u r e  in these r e g i o n s ,  with  i n f l u e n c e s appeared  a t Van  d i s t r i b u t i o n s to  harbour mouth,  south t r a n s e c t ,  f l u c t u a t i o n s were observed  that  the  been  probable evidence  shallow surface layer,  nearer the south shore.  associated with  the  during  e b b h a v e now  In g e n e r a l ,  i n the property  been d e s c r i b e d .  a t Van 1 7 ,  20 m.  Inlet.  Below t h i s  were noted a l o n g a n o r t h  Narrows,  a p e r i o d of moderate  has b e e n i d e n t i f i e d  situations  Arm,  11  s t u d y w h i c h c o u l d be u s e d a s v e r i f i c a t i o n o f  i n f l u e n c e s over  investigated  least  Van  Summary  Tidal  greater  w e r e made w e s t o f  sampled.  for  CHAPTER 4 A N C I L L I A R Y 4.1•  Meteorological 4.1.1  The Burrard water  INFORMATION  annual Inlet  input  partially  Parameters  Precipitation c y c l e o f p r e c i p i t a t i o n on t h e w a t e r s h e d s  i s an i m p o r t a n t  determines  Inlet  have  been e x a m i n e d .  Buntzen Lake -  i n determining  river  four  d i s c h a r g e , which  These  stations  surrounding  the cycle of  the d i s t r i b u t i o n of s a l i n i t y .  precipitation patterns,  fresh  i n turn  To i d e n t i f y  i n the v i c i n i t y of  the Burrard  include:  located approximately  km s o u t h e a s t  of the  B u n t z e n power h o u s e s w h i c h a r e l o c a t e d on t h e e a s t e r n  shores  I n d i a n A r m , between  b)  factor  to the i n l e t through  basic  a)  *>  Port  Moody  Gulf Refinery  of  Burrard  Inlet,  of  station  Van 3 9 .  c)  Point  d)  Vancouver of  presented  i n Figure  l o c a t e d w i t h i n a few hundred shore approximately  l o c a t e d on P o i n t  International  monthly  -  Airport  harbour-mouth  -  Grey w i t h i n  station  metres  1 km e a s t  2 km o f t h e i n l e t .  l o c a t e d 7 . 5 km s o u t h  station,  p r e c i p i t a t i o n values  southeast  Van 1 1 - 8 .  f o r these four  stations are  4 . 1 ( a ) , f o r t h e p e r i o d May 1974 t o O c t o b e r  a l l stations,  of  Ind 1 . 5 and Ind 2 .  on t h e s o u t h  (UBC) -  the southern  Total  At  Grey  stations  3.7  s i m i l a r annual  c y c l e s were o b s e r v e d .  p r e c i p i t a t i o n maxima f o r 1974 o c c u r r e d i n December  at three  1975.  Annual stations,  38 with  t h e November t o t a l  t h e December  value.  October  at a l l  1975  and i n J u l y year,  with  1975.  than J u n e ,  absolute  by t h e  stations.  in July  of  observed  less  totals  than  summer month was e x p e r i e n c e d  at  all  four  The  Port  d u r i n g months to  Point  to w i t h i n  Air  Because o f seasonal Inlet  Moody. of  is considered.  Gulf Refinery, Similar  be g r e a t e r  about  exception,  Buntzen Lake,  the  followed  Vancouver  same,  and  Differences  were  between  t h a n 400 mm. 1974,  values  In  summer  at  all  were periods  four  stations  a few m i l l i m e t r e s .  In  a i r temperature Figure  meteorological  Point  patterns  totals  h i g h p r e c i p i t a t i o n , and  i t s c l o s e r e l a t i o n s h i p to  for  either  Temperature  d i s t r i b u t i o n of  temperatures  in  each  similar,  Without  G r e y and  nearly  low p r e c i p i t a t i o n , such as i n August  4.1.2  than  s t a t i o n s were  considerably.  were v e r y  those at  i n O c t o b e r 1975  were e q u i v a l e n t  in  1974  s i m i l a r l y r e c o r d i n g much h i g h e r  varied  Gulf Refinery.  s t a t i o n s were g r e a t e s t observed  minima o c c u r r e d i n August  p r e c i p i t a t i o n was r e c o r d e d a t  Airport  consistently  period occurred  September.  patterns  Moody  International  the e n t i r e  surpassing  being s u b s t a n t i a l l y higher  1975  precipitation totals  Port  Annual  1974  and A u g u s t  maximum m o n t h l y  station marginally  E x t r e m e maxima f o r  July or  While the  the a i r p o r t  A p a r t i c u l a r l y wet  totals  June or A u g u s t ,  at  Grey  (UBC),  4.1(b)  sea s u r f a c e t e m p e r a t u r e , at stations  are  stations  at  were o b s e r v e d a t a l l  surrounding  presented monthly Buntzen Lake,  and t h e V a n c o u v e r  the  the  mean  air  Port  International  stations with winter  Burrard  minima  2 ° C o c c u r r i n g i n J a n u a r y and F e b r u a r y and summer maxima o f  Moody Airport. of  about  18UC  o c c u r r i n g i n J u l y or August.  temperature  curves  in July  corresponding periods of months. less  Absolute  1974  higher  The d e p r e s s i o n s n o t e d  and i n A u g u s t  least  stations  be i t s  of  high values  position further  and i t s  lower a l t i t u d e  4.1.3 It with  vertical winds  east-west  winds of  measurement  Diurnal  reason  for  Gulf Refinery  region of  may  stations  winds  are  and s h i f t i n g t o  due t o  the west  the  present  l i k e l y due t o sites,  (only  orientation  study  (personal  local  in early  topography, in  the blowing  morning.  s e l d o m e x c e e d i n g 25  those  in fall  and  communication  International  km/hr  winter.  few t i m e - s e r i e s  p e r i o d are not  of  considered to -  Pacific at  Airport  been a c c u r a t e l y r e c o r d e d ) .  as e a r l i e r commented,  Inlet  on  typically  l o c a l i z e d topographic e f f e c t s  the Vancouver  have  and  oriented  identified,  maxima  Burrard  transport  predominantly  l i g h t w i t h monthly  are c o n s i d e r e d to  east-west  Moody  were  site.  that  the d i r e c t i o n records f o r  available for  AES)  these  at  G r e y and A i r p o r t  i n the  has n o t e d  area are  p a r t i c u l a r l y good q u a l i t y  data  The  a n d o n l y o c c a s i o n a l l y r e a c h i n g 35 k m / h r  general,  Service,  Point  on s u r f a c e l a y e r  (1971)  Inlet  night  Winds a r e g e n e r a l l y  In  c o n s i d e r winds  Tabata  direction.  i n summer,  Port  than the Buntzen Lake  their effects  Burrard  from the e a s t a t  the  temperatures  altitude.  the  for  the  Winds  mixing.  i n the  i n summer a t  i n l a n d than  i s necessary to  respect to  agree w e l l w i t h  i n a n y g i v e n month  i n the case of w i n t e r  B u n t z e n L a k e c a n p o s s i b l y be a s c r i b e d t o observance  the  p r e c i p i t a t i o n e a r l i e r noted  d i f f e r e n c e s between  t h a n 2 ° C and a t  1975  in  be  Weather  the direction  Assuming a basic  wind speed i n f o r m a t i o n  for  40 the Burrard  Inlet  area  i s presented  18-month r e c o r d s o f monthly Atkinson, records  and V a n c o u v e r  are  duration station  abandoned  of  p e r i o d March to  maximum v a l u e s the  south  while  i s from the  First  Narrows  The  the J e r i c h o September  shore of  generally  Yacht  1975.  the  however,  were most f r e q u e n t l y excess of  board s h i p d u r i n g the October  16,  Figure speeds at trend  to  Point  Two  four  marine  partial  months traffic  This  stations  km/hr,  somewhat  and  position at  of  along lowest  Arm.  It  the  The  maximum w i n d s  s t u d y w e r e 63 k m / h r f r o m t h e e a s t a t  speeds,  harbour data  can  arm,  i n f a c t were r e c o r d e d  two o c c a s i o n s .  mean  reaching  No t i m e - s e r i e s  25 c r u i s e s w h i c h e n t e r e d and  the  reported  sheltered  Indian  was  located  the northwestern  speeds.  control  station  through  t y p i c a l l y r e g i s t e r e d the  greatest  light,  4.2(a),  be winds  in recorded  station  on  Van  11,  1975.  4.2(b)  i s presented  the a i r p o r t  station  h i g h e r wind speeds  Most  importantly,  were  infrequent  hours.  calm or  35 k m / h r on o n l y  10 and 18  representative  during the  the  which reported  Jericho,  i n i t s exposed  for  Gate B r i d g e .  The more e x p o s e d  recorded the  that  Club,  approaches,  Figure  r e c o r d i s from a s t a t i o n  r a n g i n g between  are a v a i l a b l e from a s t a t i o n noted,  Lion's  final  d u r i n g December.  Point Atkinson  entrance  record, of  the  In  stations.  first  1974.  speeds m a i n l y  Airport  The  t h e apex o f  i n August  on t h e j e t t y  monthly  International  f r o m May 1 9 7 4 ,  4.2.  mean s p e e d s a r e p l o t t e d  p r e s e n t e d as w e l l .  located at  in Figure  however,  to  over  i n the it  i l l u s t r a t e the the d u r a t i o n  p e r i o d December  i s noted  a n d when o b s e r v e d ,  of  that  winds  lasted only  for  v a r i a b i l i t y of the  study.  through  The  March i s  i n excess of the  wind  25  period of  noted.  km/hr a  few  41 From t h e s e collecting suggested  to  that  much o f  the  Inlet  and  Indian  by t i d a l  i s expected  to  time,  Arm.  Inlet  Runoff  The  primary  -  Campbell  descriptions discussion  brief  on t h e  B u n t z e n Power  a minor  by w i n d s .  it  is  role  in  River  (most  of  and t h e  runoff  into  from the  features  detail  The  the  north  Lynn C r e e k ,  and  small  west.  the  the  to  Burrard  (1962),  of  these  from these  study  the  likely  following  p e r i o d May 1974  numerous  winds,  properties.  brief  papers  to October  a r e a have  s i g n i f i c a n t l y through  River,  than  s i g n i f i c a n c e near  1.2.  for  expected mixing,  and e s t u a r i n e  variations  f r e s h water  the  is  Vertical  processes are not  in Section  of  occasional strong  Qualitative  for  in  surface waters  be o f  These  f r e s h water  t h e Seymour  system predominantly  will  (quantitative)  runoff data  House o u t f l o w s  Inlet,  b e e n d e s c r i b e d by G i l m a r t i n  (1971).  further  Fraser  River,  than  seasonal  have been m e n t i o n e d  as t h e  the Capilano  the  periods.  and T a b a t a  presents  of  presence of  transport  p r i n c i p a l sources of  identified  rather  made  and t h e c i r c u l a t i o n  transport  c h a r a c t e r i s t i c s of  a l o n g w i t h measured  The  The  I n d i a n Arm s y s t e m h a v e (1954)  properties  In t h e  have a s i g n i f i c a n t e f f e c t  4.2  play only  be c o n t r o l l e d more by t i d a l  w i n d m i x i n g and w i n d d r i v e n for  ship in Burrard  winds  currents  by w i n d d r i v e n m e c h a n i s m .  s u r f a c e but o n l y  and f r o m o b s e r v a t i o n s  aboard  the d i s t r i b u t i o n of  be d o m i n a t e d  as w e l l  data,  considerable data  determining Burrard  historical  the  Indian  1975.  been  North River,  streams which  Arm), the  enter  42 Of t h e s e ,  only  Buntzen o u t f l o w s rivers of  historical  data  i s immediately peak  Fraser  freshet  Annual  noted  a n d Seymour  annual  the Fraser  exhibit  d i s c h a r g e maximum o c c u r r i n g d u r i n g  snow p a c k .  i s a manifestation  f o r these  a bimodal  t h e May t o  between  precipitation. October  O c t o b e r a n d December For example,  during  i n t h o s e months w h e r e  t h e C a p i l a n o a n d Seymour local  the r e g u l a t i o n  i s not expected  of lake level  to follow  high values  mean y e a r l y  River.  values,  3 4 m / s f o r Lynn Creek  rates  Capilano  his estimate  metered  rivers  general,  maxima, the  curve discharge,  Burrard  Inlet,  and e s t i m a t e d  and t h u s has  f o r Lynn Creek  a n d Seymour  data  o f mean y e a r l y  3 a n d 18 m / s f o r t h e I n d i a n  in  curve.  discharge into  a n d Seymour  of h i s estimated  As t h e 1974-1975  15% o f C a m p b e l l ' s  controlled  between  In  correlated with  As t h e Buntzen  through  maximum  heavy  produces  are well  peak  recorded  (Figure 4.1(a)).  c l o s e l y the p r e c i p i t a t i o n  f o r the Capilano  accepted the v a l i d i t y  of  4.1(a).  ( 1 9 5 4 ) h a s shown good a g r e e m e n t  discharge rates  Indian  month  in Capilano,  on t h e t i m e o f  t h e snow p a c k e f f e c t  Figure  In c o n s i d e r i n g t h e t o t a l Campbell  that  discharge curves  precipitation curve,  reflects it  the exceptionally  winter's  a second  1975 c a n be t r a c e d d i r e c t l y t o t h e p a r t i c u l a r l y  p r e c i p i t a t i o n which f e l l except  dependent  cycle.  c y c l e f o r the  smaller r i v e r s are d i r e c t runoff e f f e c t s which generate sometime  rivers.  August  t h e M a y - J u n e maxima  S u p e r i m p o s e d on t h i s  these  a single  of melting of the previous  The same m e c h a n i s m e x p l a i n s  and B u n t z e n d i s c h a r g e s .  Inspection  shape o f  discharge exhibits  rivers  three  4.3.  the general cycles  and t h e  f o r the  i n Figure  confirms  of typical  that  Rivers  discharge curves  not here presented  i n June, while the other  period  Seymour  Capilano  houses a r e p r e s e n t e d  t o be r e p r e s e n t a t i v e  annual The  are metered.  a n d f o r t h e power  curves It  the Fraser,  and f o r t h e  fall  discharge  River  will  within rates be  43 assumed v a l i d f o r  the  c o m b i n e d mean y e a r l y Rivers  present  study  discharge rate  and L y n n C r e e k o v e r  as w e l l . for  the present  Employing  the C a p i l a n o , study  period  these v a l u e s ,  Indian,  and  the  Seymour  has b e e n c a l c u l a t e d  3 a s 64 m / s .  T a b a t a has p r e s e n t e d  discharge rate  for  arguments  which i n d i c a t e that  any s e c o n d a r y s t r e a m s e n t e r i n g  Burrard  the  Inlet  mean  is  3 somewhat  less  contribution f r e s h water  t h a n 3 m / s , and a l s o t h a t  even a t  o f d i r e c t p r e c i p i t a t i o n on t h e input  is less  than  1%.  i t s maximum,  inlet  Coupling  all  surface,  the  net  to the  total  these e f f e c t s with  the  mean f r e s h w a t e r  input  3 mean B u n t z e n o u t f l o w  of  23 m / s , a r e p r e s e n t a t i v e  3 rate for  of  100 m / s  the e n t i r e  (excluding  Burrard  c a n be g i v e n  of  Inlet  to  its  the actual  of  that  Fraser  this  Burrard First  Inlet.  program, Figure  River  i s the  Narrows  importance  outflow  primary The  relative  of  Fraser  source of  presence of  i s noted  to  the  is calculated  River  other  by T a b a t a  that  Fraser  River  such water  water  which  some c o n s i d e r a t i o n  fresh  water  indicate that  i s channelled through  was v i s u a l l y e v i d e n t  it  volume  Data quoted  and i s amply v e r i f i e d  4.3(a)  contribution)  i s c o n s i d e r e d i m p o s s i b l e ; however,  sources d e s c r i b e d above. 14%  River  system.  A firm estimate enters  Fraser  11  the North Arm,  water which  i n the  surface  layer  during  the  s a l i n i t y data.  survey,  and  affects outside  on many o c c a s i o n s d u r i n g t h e  by r e s u l t a n t  to  sampling  From  mean F r a s e r  River  3 discharge rates  (at  Mission) varied  from a high of  9880 m / s  i n June  1974  3 to a low of  974 m / s  i n March of  1975.  The mean d i s c h a r g e r a t e  for  the  3 1 8 - m o n t h p e r i o d was 4 0 5 0 m / s .  Assuming  this  to  be r e p r e s e n t a t i v e ,  it  3 c a n be e s t i m a t e d through  that  on a v e r a g e  a volume  t h e N o r t h Arm t o d i s c h a r g e o f f  of  Point  445 m / s i s Grey.  The  diverted volume  of  this  44 w a t e r w h i c h a c t u a l l y sweeps a r o u n d t h e P o i n t d e t e r m i n e d by w i n d and t i d e c o n d i t i o n s a t is  noted t h a t  even i f  20% o f  to enter Burrard  any g i v e n t i m e ,  other  sources i n t o the e n t i r e  the area outside F i r s t exceeds  that  of  Narrows,  any o t h e r  however,  inlet.  It  the e f f e c t  f r e s h water  t o t h e mean i n p u t  i s thus e v i d e n t t h a t  of  Fraser River  sources.  It  will  western  harbour,  in Burrard  Inlet,  of freshwater rivers.  In  is felt  at  l e a s t through F i r s t  and p o s s i b l y e v e n the  Fraser  River  Narrows  central  Indian Arm,  however,  into  the  the  Indian  Thus, effects  Seymour River  be s e e n t o h a v e a m a r k e d e f f e c t  d i s t r i b u t i o n s and c i r c u l a t i o n  patterns.  in  this  regions.  g e n e r a l l y overshadows  d i s c h a r g e from the  from  be s e e n f r o m  i n p u t f r o m s u c h s o u r c e s a s t h e C a p i l a n o and  from the Buntzen outflows w i l l the property  i n t o the  inlet,  i n p u t much  property d i s t r i b u t i o n s presented i n subsequent s e c t i o n s t h a t freshening effect  is it  t h i s r i v e r w a t e r was t o move i n t o t h e  t h i s would r e p r e s e n t a volume e f f e c t i v e l y equal all  Inlet  on  and  45 CHAPTER 5 SEASONAL CHANGES IN WATER PROPERTY To data  support  c o l l e c t e d over  figures  the  seasonal e f f e c t s time-depth  vertical  provide  sections of temperature,  Narrows  representative  Behaviour  c r u i s e s and as p a r t  c r u i s e dates  see Table  of  5.2(a)  these f i g u r e s  stations  included with  i s dependent  each f i g u r e .  that  a l o n g t h e "11"  Finally, in  o f the August  5 . 1 0 ( a ) and ( b ) .  As t h e  l i n e to conclude at s t a t i o n  of  are presented interpretation  phase a t t h e time t h e (see s e c t i o n 3 . 2 ) i s  i n c l u d e d i s an a r r o w  t h e n s o u t h a l o n g t h e "14"  on  (for  distributions  from these data  bin information Also  First  1975 CSTD s u r v e y  Horizontal  on t h e t i d a l  outside  a n d 5 . 1 ( a ) ) was u n d e r t a k e n  s a m p l i n g commenced a t s t a t i o n  proceeded n o r t h ,  and oxygen  stations  sequence i n w h i c h t h e s t a t i o n s were s a m p l e d . indicates  area.  to  changes.  1.1(b)  column 5 ) .  and (b) t h r o u g h  tidal  an o v e r v i e w  study  density  and s a l i n i t y as d e r i v e d  were s a m p l e d ,  approaches.  i n Approaches  nine regular  as F i g u r e s  Narrows  Arm a r e d i s c u s s e d c r u i s e by c r u i s e t o  ( f o r l o c a t i o n s see Figures  2.1,  to give  the e n t i r e  sampling of the supplementary  s u r f a c e temperature  of  s a l i n i t y and oxygen  stations  salinity,  a d e t a i l e d a n a l y s i s o f annual  Detailed  First  discharge i n the harbour  c y c l e o f changes throughout  Surface  series  horizontal  and s a l i n i t y o u t s i d e  River  Harbour and i n I n d i a n  5.1  three  a set of nine pairs of  sections of temperature,  Vancouver  of the study,  property  1974 t o O c t o b e r 1975 a r e d i s c u s s e d t o i l l u s t r a t e  of Fraser  are presented f o r f i v e the seasonal  Firstly,  of surface temperature  the p e r i o d August  Secondly,  synoptic discussion of the s c a l a r  t h e 18-month d u r a t i o n  are presented.  distributions over  a thorough  DISTRIBUTIONS  A left 17-8  to i n d i c a t e the pointing  (Figure  arrow  5.1(a)),  l i n e and f i n a l l y n o r t h 11-1.  A right  pointing  again  46 arrow  i n d i c a t e s an a p p r o x i m a t e  commencing o f f north  to  Point  11-8,  c o n c l u d e a t Van 17.  sampling i s  The  i n d i c a t e d by t h e  Figure 3.1  for  identifies  tidal  It  Grey a t  i s to  reverse  be n o t e d  this  sequence,  proceeding north, tidal  phase a t  b i n number a t  bin definitions) phase a t  of  w h i l e the  the  i n c o n s i d e r i n g these f i g u r e s  varies  station  As c a n be s e e n f r o m F i g u r e 5 . 1 ( a ) ,  in  the north-south  separation. is  noted  noted to  For  i n the  g e o g r a p h i c a l l y due t o  direction is generally  this  reason,  contouring  i n the e a s t - w e s t  the east of  necessary.  plotted  thus  as s o l i d  is  the d e n s i t y butions,  (see  the arrow  head  that  the degree  station of  of  l i n e s of  Similarly,  in areas  extrapolation  of  of  the  separation  east-west structure  stations, to  the  contours  than  south  has  is and  been  have been p l o t t e d  using  interpolated  contours  lines.  of  Figures  to which density  surface waters.  at  a r e c a s e s w h e r e much f i n e r  d i s t i n g u i s h i n g these from the  and s a l i n i t y r e s p e c t i v e l y ,  contours  grid,  the arrow  irregularity  one h a l f  along north-south  direction.  the s t a t i o n  Comparison  degree  there  the  In s u c h i n s t a n c e s , smooth c u r v e s  dashed l i n e s ,  of  of  sampling.  contour d e t a i l grid.  then  commencement  b i n number  the c o n c l u s i o n of  sampling  then s o u t h ,  the  tail  with  As  5.1(b)  and 5 . 2 ( a )  f o r August 1,  1974,  of  the d e n s i t y  so s i m i l a r , l i t t l e a d d i t i o n a l  attention  i l l u s t r a t e s the  i s c o n t r o l l e d by s a l i n i t y  the s t r u c t u r e  section.  w h i c h show d e n s i t y  Thus,  for  and t h e  information  c o n s i d e r a t i o n of  i s r e s t r i c t e d to  in these  s e c t i o n s of  these  (as  o^)  high  coastal  salinity  i s provided surface  s a l i n i t y and  by  distri-  temperature.  By now d i s c u s s i n g annual  cycles  of  the p a i r s of  figures  in chronological sequence,  s u r f a c e s a l i n i t y and t e m p e r a t u r e  approaches are d e s c r i b e d .  i n the  Also discussed are various aspects of  c i r c u l a t i o n which are apparent  from these d i s t r i b u t i o n s .  August  and  1,  The  1974  (Figures  harbour  5.2(a)  (b))  s e c o n d a r y s t a t i o n g r i d i n t h e h a r b o u r a p p r o a c h e s was  s a m p l e d on A u g u s t  1,  1974,  at  a t i m e when t h e  r a t e was h i g h , t h e t i m e b e i n g l e s s discharge.  Salinities  of  Fraser  t h a n two m o n t h s  first  river discharge  since  maximum  6 . 8 6 ° / o o o b s e r v e d a t s t a t i o n Van 1 1 - 8  7 . 4 9 ° / o o o b s e r v e d a t s t a t i o n Van 1 1 - 5  approximately  h i g h w a t e r on t h i s d a t e w e r e among t h e approaches throughout  surface  t h r e e hours  lowest observed i n  the e n t i r e study.  This  and before  the  i s considered to  be  e v i d e n c e o f N o r t h Arm w a t e r s w i n g i n g n o r t h e a s t w a r d s a r o u n d P o i n t on t h e  rising  tide.  A l s o a p p a r e n t on t h i s s a l i n i t y f i g u r e  high s a l i n i t y core i n the north c e n t r a l r e g i o n , which i s as a m a n i f e s t a t i o n o f ebb f l o w t h r o u g h Fraser River water north. of  A further  First  Narrows  i n d i c a t i o n of  temperatures  t h i s flow i s the s i m i l a r  and w i t h v e r y  Large h o r i z o n t a l  o b s e r v e d between t h e w e l l  shaped  of  o c c a s i o n (September  3,  1975)  i n the  tongue  river also  t h e e a r l i e r ebb f r o m off  Point  Grey.  was s u c h a r a n g e o f  observed i n t h i s area during a s i n g l e  the  5.2(b).  s a l i n i t y g r a d i e n t s were  mixed waters  to  l a t e summer c o n d i t i o n s w i t h  low s a l i n i t i e s  t h e n a r r o w s and t h e f l o o d i n g r i v e r w a t e r s other  by  t o t h e s o u t h and by N o r t h S h o r e s t r e a m w a t e r  These d i s t r i b u t i o n s a r e r e p r e s e n t a t i v e o f  influenced water.  rather  interpreted  flanked  r e l a t i v e l y l o w e r t e m p e r a t u r e w a t e r o b s e r v e d on F i g u r e  high water  is a  Grey  cruise.  inside  On o n l y  salinities  one  August  29,  1974  (Figures  5.3(a)  On t h i s s e c o n d A u g u s t salinity August rates  and  cruise,  (b)) marked i n c r e a s e s i n  and c o r r e s p o n d i n g d e c r e a s e s i n t e m p e r a t u r e  surface  (from e a r l i e r  l e v e l s ) were r e c o r d e d , c o n s i s t e n t w i t h d r o p p i n g r i v e r d i s c h a r g e and d e c r e a s i n g a i r t e m p e r a t u r e s .  observed o f f  P o i n t Grey  just after  The  tongue of  t h e ebb had s a l i n i t i e s  1 0 ° / o o h i g h e r t h a n t h o s e r e c o r d e d a month e a r l i e r . i n c r e a s e d by g r e a t e r  1 ° to  identical  sequence of  1 0 ° / o o to near 5 ° / o o .  2° during August.  1975  almost  Maximum s a l i n i t y  For  s a m p l i n g , the  similar  l a t e August  (Figures  5.4(a)  and  salinities  Temperatures tidal  dropped  s e c t i o n s do n o t  clearly  in Figure  l a t e August  c r u i s e and  this  F e b r u a r y c r u i s e on w h i c h t h e s e c o n d a r y s t a t i o n s i n t h e a p p r o a c h e s n e x t s a m p l e d a l l o w s no d e t a i l e d d i s c u s s i o n  provide  i l l u s t r a t i o n of  Salinities region,  The  the u n i f o r m i t y  r e g a r d i n g the  of  late winter  to the north from small  however,  conditions.  between 2 7 ° / o o and 2 8 ° / o o were o b s e r v e d o v e r most o f  appearing at  low water  to the  i l l u s t r a t e s minor freshening at  streams along the North Shore.  6 . 0 ° C were r e c o r d e d a t most s t a t i o n s .  ( i n f l u e n c e d by  southwest.  The  26°/oo  t h e s u r f a c e due t o  Uniform  were  transition  February c r u i s e does,  w i t h a m a r g i n a l l y lower s a l i n i t y tongue  Arm w a t e r )  to  conditions.  5.2.  (b))  An a l m o s t s i x - m o n t h gap b e t w e e n t h e  f r o m summer t o w i n t e r  temperatures  S l i g h t l y higher  the North contour runoff of  5.5°  temperatures  were a s s o c i a t e d w i t h the r i v e r w a t e r  to the southwest w h i l e m a r g i n a l l y  lower temperatures  runoff  north.  c h a r a c t e r i z e d the  by  c o n d i t i o n s and an  show t h e e b b i n g p l u m e o f m i x e d w a t e r w h i c h was s o e v i d e n t  February 22,  water  than 4 ° / o o w h i l e the observed range of  dropped from g r e a t e r than generally  river  i n f l u e n c e d water  to  the  S u r f a c e w a t e r s o b s e r v e d on t h i s c r u i s e w e r e t h e m o s t d e n s e  of  any s a m p l e d h e r e d u r i n g t h e e n t i r e  May 3 0 ,  1975  (Figures  By l a t e M a y , its  level  5.5(a)  the Fraser  of August  1974  and  survey.  (b))  discharge rate  (Figure  4.3(a))  had a g a i n i n c r e a s e d t o a b o u t  being j u s t  less  salinities  being about 2 ° / o o g r e a t e r .  t h a n on A u g u s t  1,  1974  levels.  9°/oo, (Figure  The r a n g e  w i t h maximum 5.2).and  continued  During  and s o u t h c e n t r a l salinity Figure  tongue of  5.5(b).  River water  harbour mouth, Figure  In t h e  5.5(a),  and t h e  through  the  outflow  The  centre  s e c t i o n ) a p p e a r t o mark a n a p p r o x i m a t e  the  the r i v e r waters northeast. southeast east of  June 13,  Again,  the southwest it  is well  and t h e e b b i n g w a t e r s  to note  that  detail  1975  to  of  Narrows the  between  the  i s lacking to  the  undertaken  17-8.  (Figures  5.6(a)  and  (b))  These d i s t r i b u t i o n s , drawn f r o m : d a t a f o l l o w i n g t h e May c r u i s e of  boundary  i n E n g l i s h Bay s i m p l y b e c a u s e no s a m p l i n g was  station  tongue  1 5 ° / o o i s o h a l i n e and t h e 1 5 . 5 ° i s o t h e r m ( n e a r  to  (Figure  5.5)  collected  o n l y two w e e k s  i l l u s t r a t e a high v a r i a b i l i t y  s u r f a c e c o n d i t i o n s i n the approaches.  Although  of  low  from F i r s t  was e v i d e n t . of  and spanned  southeastern  low t e m p e r a t u r e  ebb,  still  t h e r e was e v i d e n c e  a s i n d i c a t e d by t h e  l a t e r stages of  salinities  16°C.  the e a r l y hours of ebb,  i n f l u e n c e from Fraser  of  minimum  S a m p l i n g on t h i s c r u i s e commenced a t s t a t i o n Van 1 1 - 8 ebb c y c l e .  had  Water t e m p e r a t u r e s , w h i l e  q u i t e u n i f o r m had i n c r e a s e d t o g e n e r a l l y 1 5 ° t o  a full  approximately  and a i r t e m p e r a t u r e s  i n c r e a s e d c o n s i d e r a b l y from l a t e February salinities  had c l i m b e d t o  Fraser  discharge  50 rates  increased i n the  i n t e r v e n i n g two w e e k s ,  o b s e r v e d on t h i s J u n e c r u i s e generally in  over  the o u t f l o w i n g water  temperature  over  the  low s a l i n i t y water  a tongue o f water  through  t h e two-week  the temperature d a t a , southwest.  were salinities  were c o m p a r a b l e ,  increase in  t h e r e was no e v i d e n c e i n May.  Instead,  tongue e n t e r i n g the harbour  As s t a t i o n s Van 1 1 - 8 high water,  of  a n d Van 1 1 - 5  mouth  were sampled  t h i s tongue must have  at  been  The w a t e r m u s t have come f r o m  west  P o i n t Grey as any c o n t r i b u t i o n f r o m t h e s o u t h w o u l d  w o u l d be a g y r a l  circulation,  A plausible explanation  s e t up on t h e p r e v i o u s e b b .  a l o n g t h e N o r t h S h o r e on t h e e b b c o u l d f o r c e a c y c l o n i c from n o r t h to south o u t s i d e the to flood could provide  The  flow  h a r b o u r e n t r a n c e , w h i c h on t h e  turn  high s a l i n i t y water  off  P o i n t Grey as o b s e r v e d . such  c i r c u l a t i o n w i t h d a i l y mean w i n d s p e r s i s t i n g f r o m t h e n o r t h w e s t a t moderate  outflow  return  W i n d c o n d i t i o n s i n t h e p r e c e d i n g d a y s had b e e n c o n d u c i v e t o  speeds of  p o s s i b l y p u s h t h e N o r t h Arm w a t e r influence.  of  S i m i l a r i n d i c a t i o n was s e e n  s u b s t a n t i a l l y lower s a l i n i t y .  west northwest  and  2 to 3°/oo higher than those  a s s o c i a t e d with the previous f l o o d .  have been of  cycle  ( c o n s i s t e n t w i t h the  Point Grey.  of a cool  the time of  and/or north of  Narrows  period),  having s a l i n i t i e s  salinities  W h i l e maximum  t o t h e w e s t w h i c h was a p p a r e n t  r e s i d e n t w a t e r was o b s e r v e d o f f  approximately  First  i n June were h i g h e r  air  from the  an e q u i v a l e n t t i d a l  h i g h e r t h a n t h o s e r e c o r d e d i n May.  water temperatures  in  surface  10 t o 22 k m / h r .  southward,  removing  These  to  could  i t s usual  5a July  2 5 , 1975  (Figures  Although  the Fraser  between t h e June generally  5.7(a)  (Figure  and ( b ) )  River  discharge level  5 . 6 ) and J u l y  cruises,  s a l i n i t y decreases of  5 ° / o o and 8 ° / o o were r e c o r d e d i n J u l y  s a m p l i n g sequence and c o m p a r a b l e t i d a l waters  had peaked i n t h e weeks  through  First  Narrows  cycle.  had s a l i n i t i e s  18°/oo decreasing to the west,  of  1 0 ° / o o t o 1 2 ° / o o i n t h e a p p a r e n t ebb f l o w . increased to the west.  the temperature d i s t r i b u t i o n .  surface temperature  identical  While i n June,  cruise  recorded  On t h i s  ebbing 16°/oo  salinities  occasion,  S i m i l a r f e a t u r e s were o b s e r v e d  Water t e m p e r a t u r e s  r e f l e c t maximum a i r t e m p e r a t u r e s r e c o r d e d i n J u l y of  an  of approximately  to  salinities  the July  over  i n excess o f 20°C 1975.  The d i r e c t i o n  g r a d i e n t v a r i e d a s w o u l d be e x p e c t e d f r o m t h e  observed s a l i n i t y g r a d i e n t s .  Temperatures  near F i r s t  Narrows  increased  to  the west i n June  (approximately  1 5 . 5 ° t o 1 7 . 0 ° C ) and d e c r e a s e d  to  the west i n J u l y  (approximately  20.0° to  The d e c r e a s e d s a l i n i t i e s manifestation  18.5°C).  observed- i n J u l y  are i n t e r p r e t e d as  o f t h e l a r g e volume o f f r e s h w a t e r e n t e r i n g t h e approaches  through  t h e N o r t h Arm i n t h e w e e k s s i n c e  general  freshening  of  the June c r u i s e ,  i n the e n t i r e system.  The v a r i a t i o n s  g r a d i e n t are not so r e a d i l y e x p l a i n e d .  (one d a y p r i o r t o c o l l e c t i o n showed s a l i n i t i e s  a t Van 17  Observations  T h i s marked i n c r e a s e t h r o u g h  however, July  25.  causing a in direction  on J u l y  of samples from which Figure  First  Narrows  at t h i s p a i r of s t a t i o n s .  low w a t e r . most  The i n d i c a t i o n f r o m F i g u r e First  1975  7.9°/oo  i s consistent with  i s of low s a l i n i t y water ebbing through A l l evidence from other  24,  5 . 7 was d r a w n )  a n d Van 24 t o be a p p r o x i m a t e l y  and 1 8 . 6 ° / o o r e s p e c t i v e l y i n t h e l a s t h o u r o f e b b b e f o r e  observations  in  Narrows  5.7(a)  on  c r u i s e s w o u l d s u g g e s t t h i s t o be an  unlikely of J u l y  occurrence.  A more r e a s o n a b l e e x p l a n a t i o n o f t h e o b s e r v a t i o n s  25 w o u l d be m i n o r  i r r e g u l a r i t y i n t h e ebb f l o w .  If  t h e ebb  w e r e c o n f i n e d t o a m a r g i n a l l y more n o r t h e r l y a n d n a r r o w e r band usual,  t h e w a t e r s a c t u a l l y s a m p l e d a t V a n 17 may n o t i n f a c t  passed out of F i r s t  Narrows.  basis  5.7(b)  If  s u c h were t h e c a s e ,  5.7(a)  ( b o t h d a s h e d ) w e r e d r a w n on t h e  o f o n l y a s i n g l e s a m p l e (Van 1 7 ) ,  reasonable.  have  As t h e 1 0 ° / o o c o n t o u r o f F i g u r e  and t h e 2 0 ° C c o n t o u r o f F i g u r e  than  t h i s e x p l a n a t i o n seems  i t w o u l d be e x p e c t e d t h a t  more  dense w a t e r s a s s o c i a t e d w i t h t h e ebb w o u l d have p a s s e d t o t h e n o r t h Van 17 a t t h e t i m e t h e s e s a m p l e s w e r e t a k e n ,  and t h a t  of  t h e sampled  w a t e r was a c t u a l l y r e p r e s e n t a t i v e o f a m b i e n t c o n d i t i o n s o u t s i d e t h e Narrows.  August  19,  1975  (Figures  5.8(a)  and ( b ) )  Data f o r t h e s e d i s t r i b u t i o n s were c o l l e c t e d Fraser at  River discharge rate  the time of the J u l y  tidal  had d r o p p e d t o n e a r h a l f  cruise.  d u r i n g the August  salinities  low water  i n conjunction with the t o t h e commencement  The s a l i n i t y F i g u r e  5.8(a)  o f an e b b , c o n s i s t e n t w i t h s a l i n i t i e s  i n l a t e August  uniformity shows  of the previous year  Only t o the southwest  o b s e r v e d on an e b b i n g  (Figure 5 . 3 ( a ) ,  eastern  i n t h e v i c i n i t y o f s t a t i o n s Van  and 1 1 - 8 was t h e i n f l u e n c e o f l o w s a l i n i t y r i v e r w a t e r sampling  of  g e n e r a l l y between 1 7 ° / o o and 1 8 ° / o o t h r o u g h most o f t h e a r e a  on t h e t a i l  portion).  fact,  i t s magnitude  sampling, generally explains the  o b s e r v e d i n l a t e summer 1 9 7 5 .  tide  This  s e q u e n c e o f l a t e ebb t h r o u g h  flood,  a t a t i m e when t h e  11-5  observed:  t h e r e was c o m p l e t e d a t t h e commencement o f t h e f l o o d .  Temperatures  i n the area  (Figure 5.8(b))  showed s i m i l a r  uniformity  in  53 the range 1 6 . 5 ° to  1 7 . 5 ° C , s l i g h t l y warmer t h a n i n t h e f i n a l  the previous August  a s w o u l d be e x p e c t e d w i t h t h e  temperatures  r e c o r d e d i n 1975  September  1975  3,  (Figures  The d i s t r i b u t i o n s o f to  than  5.9(a)  isotherm  (Figure 5.9)  flooding  t i d e f o r e a r l y September.  Narrows,  harbour mouth. was  The  and s a l i n i t y i n w a t e r s  approximate  observed  1 5 ° / o o i s o h a l i n e and t h e  are r e p r e s e n t a t i v e of  suggesting t i d a l  air  and (b))  the  i n d i c a t e s u b s t a n t i a l i n f l u e n c e of  h i g h e r mean  of  1974.  temperature  t h e s o u t h and t o t h e e a s t o f  First  in  week  14.5°  a m b i e n t c o n d i t i o n s on a  The r e l a t i v e l y l o w s a l i n i t i e s Fraser water  into  f l o o d i n g through temperature  would  the v i c i n i t y  the  of  southwestern  decrease s i n c e August  19  2.5°C.  These d i s t r i b u t i o n s p r o v i d e f u r t h e r  evidence of  the  anomalous  i n t r u s i o n o f d e n s e w a t e r m a s s e s a r o u n d P o i n t A t k i n s o n w h i c h was e a r l i e r described  in Section 3.3.4.  salinities  up t o  (see F i g u r e  5.3),  water  the mid p o i n t  t h i s w a t e r was s e e n t o e x t e n d  central  s e c t i o n s of  e x p l a i n e d as w a t e r s mouth o f  Whether they  in Burrard  of  Inlet  the f l o o d c y c l e .  Figures  3.13(a)  It  Again,  Strait  (b)  d e n s e w a t e r mass p a s t s t a t i o n Van 1 1 ,  those  this station  Influence and  north  such o b s e r v a t i o n s must from  be  the  outflowing  from  of Georgia o r i g i n i s not d i s c e r n i b l e  i s noted t h a t  and  at  the e n t i r e northwest  t h e s e be s u r f a c e w a t e r s  be o f  present data base.  observation.  up t o 2 . 5 ° C b e l o w  being advected around P o i n t A t k i n s o n  Howe S o u n d .  having  have been c e n t r e d n e a r  through  the approaches.  Howe Sound o r w h e t h e r from the  anywhere  was r e c o r d e d t o  Van 14 a t a p p r o x i m a t e l y of  i n s t a n c e a w a t e r mass  1 0 ° / o o a b o v e and t e m p e r a t u r e s  w h i c h w o u l d be e x p e c t e d f o r time  In t h i s  identify  this  i s not a unique  the passage of  on t h e same f l o o d c y c l e ,  a  similar only  a  54 few hours after the above described conditions were recorded.  October 10, 1975 (Figures 5.10(a) and (b)) Observations taken in the final weeks of the survey illustrate an approach to winter conditions.  On a tidal cycle through high water  to the commencement of ebb, salinities in the range 24°/oo to 26°/oo were observed through most of the area. As usual, a low salinity tongue of Fraser River influenced water was seen intruding around Point Grey. Temperatures in the range 11° to 12°C reflected the continuing seasonal drop in air temperature.  Excepting the river water to the  west, evidence of the winter uniformity observed in the previous February (Figure 5.4), was clear.  5.2  Overview to Annual Cycles (Time-Depth Sections)  General features of the annual cycle of changes in the property distributions throughout the entire system can be interpreted from timedepth sections at key stations.  Spanning the full 18-month sample  period, such figures are presented to illustrate seasonal behaviour, while subsequently, vertical sections are discussed in a more detailed treatment of annual changes.  Main line stations Van 11, 24 and 34  and Ind 1 and 2 are representative of conditions in the various regions of the study area.  Sections at each particular station (Figures 5.11 - 5.13) have been prepared from all available bottle sample data (see Table 2.1 for list of cruise dates and sample locations) for that station.  The  horizontal time scale is the same for all sections, however, the vertical depth scale varies, as water depth varies from station to station.  55 C a r e m u s t be e x e r c i s e d t o a c c o u n t f o r t h i s d i f f e r e n c e when c o m p a r i n g s l o p e s and d e p t h s o f c o n t o u r s between f i g u r e s .  Again  i t i s noted  that  the very  f i n e s t r u c t u r e o b s e r v e d on t h e l i n e s  artifact  o f t h e computer c o n t o u r i n g program used t o generate t h e p l o t s .  Sections  of temperature  (Figures  5.12(a)  from the f i v e  to 5.12(e))  5.11(a)  and oxygen  to 5.11(e)), (Figures  salinity  5.13(a)  to  5.13(e))  s t a t i o n s a r e now r e s p e c t i v e l y c o n s i d e r e d .  5.2.1  Temperature  Eighteen-month Figures  (Figures  o f t h e s e f i g u r e s i s an  5.11(a)  time-depth s e c t i o n s of temperature  to 5.11(e).  surface behaviour,  At a l l s t a t i o n s except  and t o a l a r g e d e g r e e ,  a r e p r e s e n t e d as  Ind 2 t h e near  the subsurface behaviour of the  temperature  regime i s c l o s e l y  coupled t o the annual  temperature  (Figure 4.1(b)).  At  cycle of a i r  Ind 2 t h e e f f e c t s o f d i r e c t  heating  and c o o l i n g a r e c o m p l i c a t e d a t t i m e s by a d v e c t i v e e x c h a n g e o f s u b s u r f a c e waters.  At  s t a t i o n Van 1 1 ,  illustrated.  Figure  5.11(a),  this coupling of cycles  The s t u d y commenced i n M a y , a t a t i m e when a i r t e m p e r a t u r e s  were i n c r e a s i n g .  T h e same t r e n d ,  near the s u r f a c e ,  i s observed i n recorded water  i n d i c a t e d by downward  sloping contours  temperatures.  summer p r o g r e s s e d , f l u c t u a t i o n s i n w a t e r  temperatures  10 -  15 m) c o n t i n u e d t o  1 2 ° contours  i n the depth range 5 -  fluctuations  i n a i r temperature.  temperatures  through  an a p p r o x i m a t e behaviour in  is  As  (particularly parallel  F o r i n s t a n c e , t e n - d a y mean a i r  l a t e June to m i d - J u l y  remained c o n s t a n t ,  2 ° i n c r e a s e was o b s e r v e d t h r o u g h  i s p a r a l l e l e d i n the sea temperature  slope i s observed through e a r l y J u l y ,  late July.  while  This  c o n t o u r s as a d e c r e a s e  f o l l o w e d by a s h a r p d e e p e n i n g  of  the contours  is  a s s o c i a t e d w i t h a period of  mid-August, August  i n the  l a t t e r part  response i s noted,  the month.  100 m d e p t h ,  a change o f  At  September  a n d a more u n i f o r m p r o f i l e o f  M a r c h 26 b e i n g l e s s  through  of  of  a very  the s u r f a c e l a y e r decreased Generally,  nearly  isothermal water  the previous y e a r , exceeding 20°C,  A similar  c y c l e was  the second y e a r of  extremes of  w i t h maxima a t  and w i t h t h e  10 m g r e a t e r d e p t h t h a n  the  cooler  i n 1975  than  on  survey. air  1 0 ° C i s o t h e r m d e s c e n d i n g t o 40 m,  At  winter  observed  t h e s u r f a c e i n t h e summer o f  i n the preceding August.  i n 1974.  column  t e m p e r a t u r e were r e c o r d e d than  This  c o n s i s t e n t w i t h t h e m a r g i n a l l y h i g h e r summer mean a i r recorded  winter,  Minimum t e m p e r a t u r e s t h r o u g h t h e  commenced i n M a r c h , p a r a l l e l i n g t h e t r e n d o f Greater  to  through  d i f f e r e n c e s from s u r f a c e to bottom  than 0 . 3 ° .  change  1 . 5 ° C compared  temperature developed.  t h e s p r i n g and summer o f  temperature.  than  vertical  temperature  C o o l i n g was o b s e r v e d  dropped s l i g h t l y below 7 . 0 ° C .  Warming t r e n d s  The  temperatures continued through the  i n March w i t h temperature  a t Van 11  heat.  and O c t o b e r a s t h e t e m p e r a t u r e  l e a d i n g to the development  late  as l o n g e r p e r i o d s a r e r e q u i r e d f o r  the s u r f a c e .  d e c r e a s i n g a i r and w a t e r  in  in  d e p t h s e x c e e d i n g 20 m a s m a l l e r , more  f r o m May t o A u g u s t was l e s s  7 . 8 ° C at  behaviour  increased temperatures  m i x i n g and d i f f u s i o n t o d i s t r i b u t e t h e at  Similar  r e l a t i v e l y low a i r temperatures  f o l l o w e d by a p e r i o d o f  and e a r l y S e p t e m b e r .  gradual  of  mid-depth,  than 9°C observed i n September o f  1974  is  in 1975  about  again  temperatures  the pocket of  water  d i d not reappear  in  1975.  57 Over t h e 18-month p e r i o d , t h e b e h a v i o u r o f t h e t e m p e r a t u r e a t s t a t i o n s V a n 2 4 , 34 a n d I n d 1 ( F i g u r e s f a i r l y well  paralleled that  changes were s i m i l a r , particularly  5.11(c)  d i s c u s s e d above f o r Van 11.  and 5 . 1 1 ( d ) )  While the  the absolute temperatures d i f f e r e d c o n s i d e r a b l y ,  e a s t o f Second Narrows.  i s o t h e r m was o b s e r v e d a t l e s s while further  5.11(b),  to the e a s t ,  than  I n t h e summer o f 1 9 7 4 ,  1 1 ° w a t e r was f o u n d a t 50 m , p a r t i a l  i s e v i d e n t from the d i m i n i s h e d range o f temperatures  that  i n p a s s i n g f r o m V a n 11  a decreasingly important temperatures.  Outside  the 1 1 °  2 0 m d e p t h a t V a n 11 a n d V a n 2 4 ,  e v i d e n c e o f downward m i x i n g o f warm s u r f a c e w a t e r s a t S e c o n d It  Narrows.  i n the v e r t i c a l ,  t o Van 3 4 , d i r e c t h e a t i n g and c o o l i n g p l a y s  r o l e than does m i x i n g ,  First  Narrows,  i n c o n t r o l l i n g subsurface  d i r e c t heating effects  predominate,  w h i l e a t Van 3 4 , m i x i n g a p p e a r s t o be t h e c o n t r o l l i n g a g e n c y . factors  regimes  are c l e a r l y important  i n the western harbour,  Both  r e p r e s e n t e d by  Van 2 4 .  Station through  5.11(d))  i l l u s t r a t e s a more g r a d u a l  warming  s p r i n g a n d summer t h a n do t h e h a r b o u r s t a t i o n s , r e f l e c t i n g t h e  different at  Ind 1 ( F i g u r e  nature  of the c i r c u l a t i o n  this location i s less vigorous  Consequently, temperature  pattern  here.  Mixing of waters  t h a n a t s t a t i o n s Van 24 a n d 3 4 .  t h e summer i n p u t o f h e a t c a u s e s a g r a d u a l  contours.  Again,  deepening of the  the increased a i r temperatures  of the  summer o f 1975 a r e e v i d e n c e d i n t h e d e p t h o f p e n e t r a t i o n o f t h e 1 2 ° isotherm i n August, particularly Ind  compared t o t h e p r e v i o u s y e a r .  dramatic winter  temperature  T h e r e a r e no  changes c l e a r l y e v i d e n t  1 t o suggest major exchanges of water masses: t h i s ,  at  h o w e v e r , may  be a c o n s e q u e n c e o f t h e r e s t r i c t i o n o f s a m p l i n g a t t h i s s t a t i o n t o depths  less  t h a n 6 0 m.  58 Among t h e t e m p e r a t u r e is  unique.  Until  at  I n d 1 was o b s e r v e d .  heating appears The  sections, station  January of 1975, Shallower  t o have  r e s t r i c t i o n of t h i s  a pattern than  behaviour  circulation pattern,  usually  less  than  sloping  of the isotherms  expected.  with  10 m i n t h i c k n e s s .  temperature  appearing  winter  months  Below t h i s  a t Ind 2.  provide  sections.  commenced a g a i n Again  through  t h e warmer  temperature.  is indication surface  layer,  the w i n t e r ,  that  direct  of  layer  the gradual  d i f f u s i o n of a progressive  heat. rising  O c t o b e r t o December w o u l d be  commencing i n J a n u a r y o f 1 9 7 5 , marked  intrusions will  vertical  layer  5.11(e)  s i m i l a r to  10 m d e p t h ,  an o u t f l o w i n g  were r e c o r d e d a t a l l d e p t h s ,  waters  These  about  i s i n d i c a t i v e o f downwards  as observed  However,  somewhat  to a surface  Were s i m p l e c o o l i n g t o p r o c e e d t h r o u g h the contours  Figure  controlled the d i s t r i b u t i o n of  an e s t u a r i n e  of  Ind 2 ,  with  Such t e m p e r a t u r e  changes  substantially  in  cooler  decreases through  the  late  d i r e c t e v i d e n c e o f i n t r u s i o n s o f new w a t e r . be t h o r o u g h l y  detailed  As e a r l i e r noted  i n March,  i n l a t e r discussions of  f o r the other  stations,  a s i n d i c a t e d by t h e downward  summer o f 1975 i s e v i d e n t  warming  sloping  i n the behaviour  isotherms.  of the 1 1 °  isotherm.  5.2.2 In of  both  interpreting  the seasonal  fluctuations  of s a l i n i t y ,  r u n o f f and o f p r e c i p i t a t i o n a r e o f c o n s i d e r a b l e  Inspection  of sections 5.12(a)  d i s c u s s e d above distinct  Salinity  regions  in relation  through  5.12(e)  to temperature,  i n terms o f s a l i n i t y  importance.  f o r t h e same f i v e  reveals  changes.  the e f f e c t s  three  rather  stations  59 Firstly,  the region outside  by s t a t i o n Van 1 1 , distributions, River  here,  was t h e  s e c t i o n 5.1)  best  downward through  isohaline  greater  of Georgia  Salinity  at t h i s  station  salinities of  Precipitation possibly  1974,  extremes  coupled with  higher s a l i n i t y  time.  then  25 m i n  rising  in this  10 m, t h e s e a s o n a l  r u n o f f and o f p r e c i p i t a t i o n .  slightly,  at the time  direct  r u n o f f peaks  in Capilano  latter  changes Minimum  with  waters  year.  in salinity surface  r u n o f f and  4 . 3 and same  4.1(a)). year,  a n d Seymour  f o r the c o n s i d e r a b l e freshening noted Later,  of  the s u b s t a n t i a l l y  i n J u l y o f 1974 a t a t i m e o f h i g h (see F i g u r e s  waters  December,  i s consistent with recorded  of  of the 30°/oo  to approximately  i n November and December o f t h a t  d i s c h a r g e s must a c c o u n t  freshening  a result  c h a n g e was a g a i n n o t e d  i i i 1974  s h a l l o w e r than  o f both  of the  diminished  decreased from  h i g h summer p r e c i p i t a t i o n  surface at that  (May - J u l y ) . a  As r u n o f f  of  generally  discharge levels  were o b s e r v e d  relatively  Fraser  10 m d e p t h  The l e s s e r s p r i n g f r e s h e n i n g o f d e e p  i n 1975 t h a n  in Fraser  effects  surface  The p r i n c i p a l  i n both years  10 m was o b s e r v e d ,  100 m i n J u l y  A pronounced  i n May a n d J u n e .  than  caused a decrease i n the depth  than  freshet  At a l l depths  at greater  below 3 0 ° / o o i n e a r l y M a r c h ,  i n t h e month.  reflect  than  the w i n t e r  a t depth  dropping marginally  l o w e r peak  characterized  of Georgia.  discharge  of fresh surface waters.  from g r e a t e r  December.  is  (see d i s c u s s i o n of  to the S t r a i t  W h i l e r u n o f f was h i g h  t h e summer a n d i n t o  from the S t r a i t  which  a s s u m e d t o be b a s i c a l l y c o n t r o l l e d by  the peaking of Fraser  a t a l l depths mixing  i s again  i n s a l i n i t y of waters  (Figure 4 . 3 ) .  of waters  Narrows,  i l l u s t r a t e d by t h e 2 9 ° / o o a n d 3 0 ° / o o i s o h a l i n e s ,  decrease  coincident with  later  5.12(a),  d i s c h a r g e a n d by p r o x i m i t y  feature  study  Figure  First  near  River the  d e c r e a s i n g p r e c i p i t a t i o n and r u n o f f ,  60 the  presence of S t r a i t  2 8 ° / o o was f e l t . increased freshet  Fraser  passed.  abnormally  In A p r i l River  1975,  d i s c h a r g e commenced,  Finally  i n t h e l a s t weeks  of the i s o h a l i n e s at l e s s  Stations  Van 24 a n d 34 ( F i g u r e s  second r e g i o n  i n terms  seasonal  cycles  precipitation  even  and r u n o f f .  they  depths  a r e 14 m a n d 18 m r e s p e c t i v e l y ) .  depth. depth  fractionally  A t Van 2 4 , b e t w e e n barely  and 5 . 1 2 ( c ) )  depth  less  First  the narrows  (First  than  and Second Narrows  Outside  the F i r s t  3 0 ° / o o were  and Second N a r r o w s ,  as  of the occurrence of considerable mixing  20 m sill  Narrows  salinities  Such b e h a v i o u r  sill,  20 m at  this  Narrows,  is  interpreted  across both  First  Narrows.  The m a g n i t u d e a t Van 1 1 ,  of surface s a l i n i t i e s  a t Van 34 must  outflow  Indian  from  a t Van 24 i s g e n e r a l l y  a g a i n a t l e a s t p a r t i a l l y due t o m i x i n g .  lower values  Arm.  r e f l e c t the e f f e c t s  At both  stations,  c o n t r o l l e d by p r e c i p i t a t i o n a n d r u n o f f . noted  i s t o be  recorded near  r e s t r i c t e d t o near 2 7 . 5 ° / o o .  than  the  effect  r e a c h e d 2 9 ° / o o w h i l e a t Van 3 4 , i n s i d e S e c o n d  evidence  a  complicates the  at approximately  v a l u e s were  and S e c o n d  identify  At these s t a t i o n s ,  salinities  just  only  as e v i d e n c e d by t h e  A simple i l l u s t r a t i o n of t h i s  sill  of  15 m d e p t h .  5.12(b)  depth,  salinities  than  the e f f e c t s  a r e p r i n c i p a l l y c o n t r o l l e d by  s e e n by c o n s i d e r i n g maximum w i n t e r greater  than  with  d e c a y i n g a g a i n as t h e  felt,  passing through  though  exceeding  of the study,  of s a l i n i t y cycles.  of mixing of waters  salinities  the spring freshening a s s o c i a t e d  h i g h O c t o b e r p r e c i p i t a t i o n were  downturning  effects  of Georgia water with  greater  Generally  of surface  layer  changes a r e b a s i c a l l y  Significant  i n J u l y a n d i n November o f 1974 a t b o t h  f r e s h e n i n g was  of which times  r u n o f f and  61 p r e c i p i t a t i o n were  high.  Again  a t Van 24 a n d a t Van 34 i n l a t e  a n d i n m i d - M a r c h o f 1975 a d e g r e e o f f r e s h e n i n g was n o t e d few m e t r e s .  The M a r c h e v e n t  C a p i l a n o and Seymour salinity  outflow  is attributable  discharge,  from  Indian  Arm.  The J a n u a r y e v e n t  low r u n o f f f r o m t h e C a p i l a n o and Seymour w a t e r s h e d s , into  Indian  Arm a t t h i s  estuarine outflow, the  surface  i n the  At depths changes  which could e x p a l i n  simultaneous  however,  recorded  greater than  about  15 m a t t h e s e s t a t i o n s ,  salinity  d e s c r i b e d f o r Van 1 1 .  i n each y e a r  An  was n o t e d  Narrows.  Again,  i s o h a l i n e a t Van 2 4 , 5.12(c))  a lesser effect  Figure  5.12(b),  due t o l o w e r  again followed that  precipitation  Salinity and h i g h  Fraser River  stations,  the system i n 1975  with  (see  than  November a n d  period of  and Seymour  stations  Winter  high  watersheds  a t Van 1 1 ,  o f Van 24 a n d Van 34 t o t h e r i v e r m o u t h s .  the e n t i r e water  from  mixing  through  decreases r e s u l t i n g from t h i s  r u n o f f from the Capilano  the c l o s e r proximity  both  near  freshet,  discharge.  s a l i n i t y values  w e r e e v i d e n c e d more d r a m a t i c a l l y a t t h e s e to  runoff  and 2 6 ° / o o i s o h a l i n e a t  d e s c r i b e d f o r Van 1 1 ,  accounting f o r decreases i n absolute 1974.  c o l u m n was a f f e c t e d  due At  as s a l i n i t i e s  fell  b e l o w 2 9 ° / o o a t 50 m a t Van 24 and b e l o w 2 7 ° / o o a t 50 m a t Van 3 4 . time  l a g i s suggested  effect  of  abrupt  at the time of Fraser R i v e r  outside  December  high  the low s a l i n i t i e s  entering  behaviour  low  occurred at a time  due t o t h e d e c r e a s e d s a l i n i t y o f s o u r c e w a t e r s  Van 3 4 , F i g u r e  in  harbour.  f r e s h e n i n g was n o t e d  28°/oo  peak  t i m e c o u l d be r e s p o n s i b l e f o r l o w s a l i n i t y  roughly p a r a l l el l e d those  First  i n the top  to a secondary  possibly coupled with  January  as t h e downturn  down t o a p p r o x i m a t e l y  i n t h e downward of contours sill  depth.  propogation  appeared  of t h i s  l a t e r at  The c o n t o u r s  A  freshening  increasing  reversed t h e i r  depths downward  62 trends  at  progressively  runoff diminished (see differences Narrows  i n the  through  stratification estuarine  intensity  to  still  of e s t u a r i n e  the  it  downwards  d i m i n i s h e d even  disappeared,  as m i x i n g o f w a t e r s influence.  For  it  that  i s noted than  peak  runoff,  an i n f l o w i n g  that  reference  the  depth  Indian  at  these  Finally,  the  Arm c o n s t i t u t e s  a third  s a l i n i t y patterns.  temperature  and Ind  The  2 (Figure  outflowing  further  e n h a n c e d by t h e  imately  10 m t h i c k Within  this  fresh  d i s t i n c t region stations The  as  increase dominant  Arm  exchange, at  1975  interval  and  explain  layer.  This  s a l i n i t y s e c t i o n s which  surface l a y e r through  34.  i n terms are  Ind  of 1  e a r l i e r discussed Indian  conclusion is  identify  an  approx-  which s a l i n i t y gradients  l a y e r s a l i n i t i e s are determined  the  further  an e s t u a r i n e c i r c u l a t i o n i n  surface  the  water  began t o  of  Van 24 and a t Van  5.12(e)).  inside  recorded in the  O c t o b e r 1975  pertinent  d a t a showed e v i d e n c e o f  a typical  for  estuarine  densities)  spring freshet  Later,  Finally,  Indian  therefore  depth  a t Van 2 4 .  a g a i n became t h e  s t a t i o n s were  in surface s a l i n i t y at  5.12(d))  depths  when  layer at  f r e s h water  i n l a t e r d i s c u s s i o n s of  h i g h p r e c i p i t a t i o n and r u n o f f v a l u e s fluctuations  all  of  strong  t h e weakened  source of  Narrows  maximum s a l i n i t i e s ( a n d  March.  the  and s a l i n i t i e s a t  a  as  First  i s l i k e l y that  mixing of  further,  from o u t s i d e  10 m d e p t h  January through  high.  is suggestive  which caused the observed s a l i n i t y d e c r e a s e s .  effectively  Arm w i t h  It  time of  can b e . e x p e c t e d  December  c i r c u l a t i o n across  freshening. at  through  delay  h i g h s a l i n i t i e s below s i l l  allowed greater  r u n o f f volumes  (Figure  This  c i r c u l a t i o n was e s t a b l i s h e d , w i t h  circulation  seasonal  a l l depths  4.3(b)).  the period of  as r u n o f f d i m i n i s h e d ,  greater  Figure  was g r e a t e s t ,  accounting for  narrows,  l a t e r times  predominantly  are by  63 r u n o f f and p r e c i p i t a t i o n . River  have  surface to  been q u o t e d ,  the  annual  s a l i n i t y measurements  those  presented  i n e a r l y summer a t surface  Though no d i s c h a r g e d a t a  in Figure  near the 4.3(b).  extreme  at  observed  Surface  Again  and r u n o f f v a l u e s  low s a l i n i t i e s .  1126  spaced ( i n  h PST,  1.7°/oo  analysis) PST,  December 5 ,  (below  the  t h e same s t a t i o n , well  a p o s s i b l y tenuous  Ind  the  t o which such  Less  the probable  time-depth  than  being dependent  r e a l i t y of  such s h o r t  some s p e c i f i c  precipitation  s a l i n i t y in Indian  At  of  fresh water  Ind  Arm a p p e a r s  used i n the later,  At  present  a t 0935 h  the o u t f l o w  the  o f mean r u n o f f 10 m d e p t h ,  i n the  At  and  and the  Ind  interval  it  18-month  distribution  be c o n t r o l l e d by d i f f u s i v e a n d  surface  at  could  plume f r o m  o f mean c o n d i t i o n s ,  than about to  2.  some  approximately  d e t a i l s i l l u s t r a t e d i n the  greater  near the  at  Such v a r i a b i l i t y  weak m i x i n g p r o c e s s e s , and by a d v e c t i v e e x c h a n g e . volumes  interpretation  period s a l i n i t y fluctuations  be r e a d i l y e x p l a i n e d i n t e r m s cycles.  the  on t i d e and w i n d c o n d i t i o n s .  s e c t i o n s may be u n r e p r e s e n t a t i v e  t h u s may n o t  1  not  1 8 . 3 0 ° / o o was r e c o r d e d  some 1 6 . 6 ° / o o . p o s i t i o n of  Ind  upon c o n s i d e r a t i o n o f  24 h o u r s  a surface s a l i n i t y of  this  high  explanation of  1966 UNESCO t a b l e s  2.  both  in  observed.  a surface s a l i n i t y of  be e x p l a i n e d by t h e v a r y i n g  becomes c l e a r t h a t  of  of  a change o f  Buntzen powerhouses, Given  1974,  limits  1974,  were  s u r f a c e s a l i n i t y measurements  was r e c o r d e d a t  December 6 ,  s a l i n i t y minima o c c u r r e d  r e l a t i v e l y h i g h , were  That the extent  time)  from  A s e c o n d a r y minimum  may be p u r s u e d i s r e s t r i c t e d becomes e v i d e n t closely  as i n f e r r e d  i n J a n u a r y and i n M a r c h a t  though  offering  Indian  I n d i a n Arm i s s i m i l a r  I n d 2, l o w s u r f a c e s a l i n i t i e s  these times,  the  i n November as an e x p r e s s i o n o f  r u n o f f and h i g h p r e c i p i t a t i o n .  Precipitation  head o f  t i m e s o f maximum r u n o f f .  s a l i n i t y was n o t e d  and i n J a n u a r y a t  runoff pattern  for  1,  by  increased  May t h r o u g h  July  64 caused a gradual the contours  deepening of  i n the  the  density) water  i n the water  illustration  of  observed at at  Ind  late  in  Ind  0 on t h e  spring of  Again,  from B u r r a r d  I n d i a n Arm s i l l  i n December  column a t  than  this  than  same c r u i s e s .  salinity  The  i s comparable the  as r i v e r  at  clarify  processes which c o n t r o l  by c h a n g e s  in considering this from  illustrates  1 . 0 ° / o o to absolute  less  at  figure  0.1°/oo.  changes o f  The e a r l i e r s u g g e s t i o n o f October  that  Ind  cycle closely p a r a l l e l s that provided  shifts  those  the  observed of  absolute  2,  this  that Thus, less  greater  than  130 m i n t h e  Ind  than  1,  Subsequently, diffusion  through  resulted  structure  the  higher  annual  60 m s e r v e s It  contour observed  Inlet  to  i s to  be  interval at  depth  waters at  in  depths  27.2°/oo isohalines. v e r t i c a l mixing  i n d e c a y i n g s a l i n i t i e s a g a i n above later vertical  year.  0.5°/oo.  November and D e c e m b e r ,  be s e e n more c l e a r l y f r o m  the  however,  change.  intrusion of Burrard  2 7 . 0 ° / o o through  in  previous  5.12(e)),  i s h e r e c o n f i r m e d as a s h a r p u p s w i n g was o b s e r v e d  than  and  lower.  2 7 . 0 ° / o o the  the  layer  s a l i n i t i e s were  (Figure  cycle of  at  surface  i n the  described for  depths  further  change o b s e r v e d  observed  by  salinity  a t Van 34  d i s c h a r g e r a t e s were  information  noted  lower  harbour,  10 m and 60 m d e p t h  the  presence of is  of  surface  The  pattern to  the  dictated  late January  of  evidence  depth ( a s  in  1 are c o n s i s t e n t with  1975  below  upswing  their  1.  i n November o r  mixing  p r o c e s s as s a l i n i t i e s b e n e a t h  i n 1974,  Between  Inlet  Ind  The  i s most p r o b a b l y  and f i n d i n g  as was d e s c r i b e d f o r  1975  s a l i n i t y contours.  l a t e summer m o n t h s  higher s a l i n i t y waters across  the  s e c t i o n s , the  90 m.  and As  salinity  will minimum  65 observed  between  associated with  The in  the  i n t r u d i n g waters  January exchange  the e a r l i e r presented  salinity between at  90 and 140 m d u r i n g November r e s u l t e d f r o m  Ind  through  data.  Salinity  of  2.  S a l i n i t i e s at  May,  with  depths  Shallower  associated with  May a s t h e  presence of  increasing  depths.  all  19,  than the  1975  of  about  at a l l  100 m d e p t h ,  i n t r u s i o n began t o  In t h e d e e p e r w a t e r s ,  i n October.  l e a s t 30 d a y s . greater  Nearer  the  than  surface,  Inlet  waters  5.2.3  increased  salinity the  90 m u n t i l  however,  in  early  mid-depth  to  ever  maxima  decrease  the  a late  200 m  end o f  summer  the  salinity  exchange  with  Oxygen  d e s c r i b e d above  for  5.13(a)  5.13(e).  i n the water  climb  recorded at the  50 m  commenced.  Oxygen s e c t i o n s c o r r e s p o n d i n g  through  than  s u r f a c e was f e l t  From J u n e ,  about  to  the  recorded  greater  drop again  decay of  i n c r e a s e was r e c o r d e d as a s e c o n d s e a s o n o f Burrard  depths  130 m c o n t i n u e d  near the  in  0 . 2 5 ° / o o were  2 7 . 7 5 ° / o o being  f r e s h e r waters  depths  illustrated  section i s again evident  exceeding  a maximum v a l u e  l a g g e d t h e s u r f a c e by a t  depths.  increases in excess of  salinities  continued at  lesser  Arm d e e p w a t e r s w h i c h was  temperature  J a n u a r y 3 and F e b r u a r y  d e p t h on May 3 0 .  survey  Indian  at  displacements  temperature  i n time  and l o c a t i o n t o  and s a l i n i t y a r e  While production  s u c h as d i f f u s i o n  and m i x i n g a l s o a c t  interpretation  of  seasonal  these agencies  i s complementary  and s a l i n i t y c y c l e s  already  changes to  to  presented.  of  Figures oxygen  physical processes  r e d i s t r i b u t e oxygen.  i n oxygen the  p r e s e n t e d as  and u t i l i z a t i o n  column are b i o l o g i c a l l y c o n t r o l l e d ,  those  d i s t r i b u t i o n based  interpretations  of  An upon  temperature  66 At  less  than about  concentrations ivity  (see peaks  May t o J u l y , into  are kept  15 m d e p t h a t Van high throughout  in July,  1975),  September  t h e w i n t e r months  The  the year  Georgia  oxygen  two  i n the  process of  l a t e October  at  waters. be'  s u c h an o b s e r v a t i o n  provides  further  of  Strait  importance.  greater  of  than  Firstly,  During  t h i s time of  of  a minimum,  concentration.  in  the approximate  the  the study  (A.G.  Lewis,  An  the  February  oxygen  b i o l o g i c a l consumption,  i s t o be n o t e d  that  throughout  Strait  of  to depth  communication).  changes i n  the water  i n the  oxygen  absence  surface waters  are  activity oxygen  column rich of  and s u b s u r f a c e a d v e c t i o n .  Georgia  in  productivity  when b i o l o g i c a l  r e f l e c t s downward m i x i n g o f  d i f f u s i o n of  high  personal  November t h r o u g h M a y ,  i n c r e a s e i n oxygen  column,  minimum a t d e p t h  end o f  account  high b i o l o g i c a l  p h y s i c a l p r o c e s s e s must accounts f o r  f r o m November t o surface waters,  An o x y g e n  20 m  consumption  d e c o m p o s i t i o n i s assumed t o  concentration observed at depth  coincides with  i n t e r v e n i n g months  significant  are of  as t h e y decompose.  season i n both years  is  through  surface  near the s u r f a c e , dead p l a n k t o n s i n k i n t h e water  consuming oxygen  the  even  known t o  are predominantly  detrital  May t h r o u g h N o v e m b e r .  productivity  In  11  11  oxygen  Georgia are  d i s t r i b u t i o n at depths  principal factors  the d e c r e a s e i n oxygen  interval  it  a t Van  c o n s i d e r i n g t h e oxygen  a t Van 1 1 ,  for  found  inlet,  interval  origin.  In  of  waters  i n the  product-  atmospheric  turbulent mixing of of  oxygen  and t h e  h i g h v a l u e s o b s e r v e d a t Van  As w i n d and wave c o n d i t i o n s i n t h e S t r a i t  evidence that  5.13(a),  by b i o l o g i c a l  and s o l u t i o n o f  suggest s u b s t a n t i a l  more s e v e r e t h a n t h o s e  Figure  and November 1974  and by t r a n s f e r  the s u r f a c e l a y e r .  11,  the  Again  67  assumed s o u r c e o f o x y g e n Downward m i x i n g March 1975,  f o r t h i s deeper water  when p o c k e t s  As  of water  temperature  b i o l o g i c a l production  surface to  with  replenishment.  o r s i n k i n g o f s u r f a c e w a t e r was c l e a r l y e v i d e n t  e x c e s s o f 6 . 0 ml/1 were observed stability  oxygen  in April,  h a v i n g oxygen  a t 25 t o 50 m d e p t h  and s a l i n i t y p r o f i l e s  o f oxygen  oxygen  concentrations  in in  a t a time of low  being nearly  vertical.  began t o i n c r e a s e a g a i n n e a r  concentrations  at depth  the  correspondingly  began  drop.  Oxygen c y c l e s be e x p l a i n e d through  i n terms of c o n d i t i o n s o u t s i d e  First  and S e c o n d N a r r o w s ,  As a t V a n 1 1 , prevailed Van 3 4 . oxygen  throughout  lower magnitudes  partial  concentrations  observation  outside  First  can  mixing productivity.  i n the surface  layer  p e r i o d a t b o t h Van 24 a n d  Narrows,  r e c o r d e d a t Van 2 4 .  in their  with  atmospheric the  remained  production, i n oxygen  high near  concentration  and i n J u l y  through  First  of the g e n e r a l l y  a t Van 11  (this  relative  the s u r f a c e ,  anticipated  could values  being oxygen  p o s s i b l y due t o l o c a l  oxygen  mixing  and c o n s e q u e n t  i n waters  Second Narrows.  surface waters  Narrows  A t Van 3 4 ,  p a s s i n g from  Maxima o b s e r v e d  1975 a r e a s c r i b e d t o s u c h p r o d u c t i o n .  outflowing  vertical  lower oxygen  station  i n the approaches).  i n s p i t e o f t h e downward  harbour  that  of conditions  Turbulent  passage through  explanation  a t 2 m a t Van 24 t h a n  representative  well  Narrows,  h i g h c o n c e n t r a t i o n s m u s t r e f l e c t t h e same  of these waters  observed  western  First  and 5 . 1 3 ( c )  o f w i n d s a t t h e two l o c a t i o n s p o s s i b l y a c c o u n t i n g f o r t h e  provide  values  the e n t i r e  5.13(b)  and i n s i t u b i o l o g i c a l  h i g h oxygen  s o u r c e as f o r w a t e r s  marginally  also  relatively  These  strength  mixing  a t Van 24 a n d Van 3 4 , F i g u r e s  from  Indian  It  decrease the  i n August  i s probable  Arm c o n t r i b u t e d  to  1974 as  68 keeping values  At  h i g h a t Van  34.  g r e a t e r than about  seasonal  cycle  modifications  15 m d e p t h a t  again p a r a l l e l e d that t o a b s o l u t e oxygen  b o t h Van 24 and Van 34  described for  concentrations.  Van 1 1 , A general  d e c r e a s i n g oxygen c o n c e n t r a t i o n a t depth between A p r i l followed  by a g r a d u a l  increase through the winter  March i s c o n s i s t e n t w i t h the s i m i l a r outside F i r s t  Narrows.  The  a c t u a l oxygen  by c o n s u m p t i o n and by m i x i n g . i n May 1 9 7 4 ,  cycle  with pattern  of  and November  t o a maximum  in  observed i n source waters v a l u e s a t d e p t h were c o n d i t i o n e d  From t h e h i g h s p r i n g v a l u e s a t  b o t h s t a t i o n s showed d e c r e a s e s t o b e l o w 4 m l / I  this  v a l u e b e i n g h i g h e r than t h e v a l u e s near 3 ml/1  11.  Such b e h a v i o u r  i n d i c a t e s a l e s s e r oxygen  plankton c o n c e n t r a t i o n near s u r f a c e .  depth  i n November,  observed at  demand a t d e p t h ,  a l e s s e r c o n c e n t r a t i o n of d e t r i t a l m a t e r i a l , which i n turn lesser  the  Van implying  implies a  Oxygen v a l u e s a t  depth  a t b o t h s t a t i o n s i n c r e a s e d f r o m November t o M a r c h when b o t h maxima e x c e e d e d M a r c h v a l u e s a t Van 1 1 , mixing of  oxygen  Less d e t a i l for  rich  the  surface waters  through  the  evidence of  downward  narrows.  i s o b s e r v e d n e a r t h e s u r f a c e on t h e  I n d i a n Arm t h a n  sample a t  providing further  oxygen  sections  i n t h o s e from h a r b o u r s t a t i o n s as the top  I n d i a n Arm s t a t i o n s was f r o m 5 m d e p t h  bottle  in contrast  to  b o t h 2 m and 5 m s a m p l e s w h i c h w e r e t a k e n a t t h e o t h e r l o c a t i o n s . Nevertheless,  a seasonal cycle  Ind  5.13(d),  1,  Figure  i s apparent  h i g h oxygen  i n the s u r f a c e l a y e r .  values near the s u r f a c e i n  interval  May t h r o u g h O c t o b e r a r e a s c r i b e d t o b i o l o g i c a l  oxygen.  Winter values at  At  the  production  5 m depth were c o n s i d e r a b l y lower than  of  those  69 at  corresponding depths  outside  the  l e s s e r degree  of w i n d ,  Ind  1.  exceeding  At  depths  the Arm,  wave and t i d a l m i x i n g 15 m, o x y g e n  typical  d e c r e a s e due t o d e t r i t a l  minimum  i n December  The  abrupt  Ind  1 in January  intruding greater  followed  than  During  at  both y e a r s  a l l depths  of  the  i n s i d e t h e arm t h a n  lesser mixing  effects.  The  study  radically different  interval  May t h r o u g h  typical about  with  at  Figure  i n the  about  harbour  from t h a t 1974,  a n d downwards a gradual October,  this period  mixing  only  observed  about  of  intrusion  Burrard  of  of tidal  20 m d e p t h In  was,  the  w o u l d be c o n s i d e r e d from the s u r f a c e  utilization.  At  depths  greater  As w i l l  a marginal later  s e c t i o n s , t h i s event  Inlet  evidence  elsewhere.  slight fluctuations  75 m and 125 m d e p t h  vertical  consistent  and w e a k e r  c o n s u m p t i o n was a g a i n n o t e d .  c o n c e n t r a t i o n was r e c o r d e d .  presentation  near-  concentrations  than  behaviour  water  at  were  5.13(e),  l i g h t e r winds  the  values  are f u r t h e r  greater  May.  waters  In  in  the  to  layer  concentration  i n d i c a t i n g a n e a r b a l a n c e between  and d i f f u s i o n .  d e c r e a s e due t o between  m,  into  a  a t 33 m d e p t h  seasons,  decrease in concentrations  75 m and 110  were r e c o r d e d over  2,  L e s s e r maximum  changes at  September  a gradual  Ind  75 m d e p t h b e i n g a s c r i b e d t o d e t r i t a l  between  oxygen  10 m.  the  summer t o  i s probable evidence of  i n the a p p r o p r i a t e  oxygen  however,  the  with  at  exhibited  increase extending  exceeding  i n d u c e d by g e n e r a l l y  c y c l e of  through  where J a n u a r y oxygen  previously described stations.  measured the  contour)  sill,  s u r f a c e maxima w e r e o b s e r v e d with  utilization  c o n c e n t r a t i o n observed  (see 4 . 5 ml/I  5 . 0 ml/1  a f f e c t i n g waters  concentrations  by a g r a d u a l  i n c r e a s e i n oxygen  from o u t s i d e the  a f a c t which i s c o n s i s t e n t  consumption  than  110 m  In  late  increase  be s e e n i n  in  the  c o i n c i d e d w i t h a minor  at approximately  these depths  near  t h e mouth o f northwards nearer  to  Ind  t h e mouth  bringing Ind  Indian  2.  Arm.  2,  a minor  c o u l d have  values at  intruding waters  advection  of  waters  b e e n f o r c e d by t h e  s l i g h t l y h i g h e r oxygen Such h o r i z o n t a l  oxygen  Though t h e  d i d not  previously  intrusion,  concentrations  to  greater  t h a n 80 m d e p t h  continued  resident  thus  the water  m o t i o n was a l s o l i k e l y t h r o u g h  penetrate  column  December  their  at  as  gradual  decline.  Early began. least  in January  The  oxygen  at depths  were c o m p l e t e l y at  200 m d e p t h  4 . 5 3 ml/1  1975,  a major  section at  greater  than  Ind  at  Ind  1975.  continued through A p r i l ,  recorded  a t 2 0 0 m on A p r i l  of  after  i n c r e a s e of  greater  the deepwater  vertical  1975.  i n the  than  be a d i r e c t m a n i f e s t a t i o n  following  the time of  oxygen  decrease associated with end o f  observations  in  1.5  of  depths  Indian  ml/I  5.18  ml/1  Later  at  basin values to  concentration  than  being  90 m a in  February,  presentations  be a s s o c i a t e d w i t h intrusion,  intruding waters.  began,  1975  was r e c o r d e d  increase to  Arm  Oxygen  i n oxygen  less  water  indicates that  mass.  change  maximum a t d e p t h ,  consumption  Inlet  on J a n u a r y 3 ,  p r e c i p i t a t e d by t h e  October.  the  had commenced.  show t h i s  layers,  of  a maximum o f At  than  outflow to  upper  with  intrusion  sections will  5.13(e),  the waters  A gradual  29,  Burrard  i n t r u d i n g water  at depth  well  Figure  2 r o s e from 0 . 5 3 ml/1  on J a n u a r y 2 2 ,  substantial  2,  90 m ,  r e p l a c e d by t h i s  i n t r u s i o n of  rather  I n May  the expected  and c o n t i n u e d  an  1975,  gradual  through  the  71 5.3 The  Detail  of Annual  preceding d i s c u s s i o n of  has d e s c r i b e d s e a s o n a l in  the Burrard  controlling physical  Cycles  Inlet  changes  of  seasonal  presented  i l l u s t r a t e the  time steps averaging i s the  intermediate sections)  further  t o deep  shown t o  Two s e t s o f Inlet  incorporate 2.5, It  provide  i s to  be n o t e d  that  indicated.  of  of  Indian  w h i c h were  of  the  Arm i s  vertical now  properties in  exchanges  (from the  for  station the  locations)  inlet.  stations  regular  The  at  this of  time-depth  Van 3 4 ,  both  collected at cruises.  stations  With only  stations  14, to  The 17,  Ind  0,  24,  of  Ind  1.3,  1.5,  Ind  the  Arm.  have 2.8  all  time  such of  section,  section  2,  In  survey  and  On e a c h v e r t i c a l the  the  sections.  one e x c e p t i o n ,  30 h o u r s o f  east-  sections  1,  this 1.3  27,  an  view through  sets of  used i n p r e p a r i n g  Burrard  provide  I n d i a n Arm  c o l l e c t e d as p a r t  I n d i a n Arm s t a t i o n s .  those  11,  a basically north-south  Arm d a t a  by d a t a  presented.  d a t a f r o m s t a t i o n s Van  s t a t i o n s were o c c u p i e d w i t h i n  only  processes  importance  the w i n t e r  Van 34 i s common t o  on p r e c e d i n g o r s u b s e q u e n t  locations  Of m a j o r  s e c t i o n s are j o i n t l y  (some o f )  and 3 t o  sampling at  s i x weeks.  through  2.8  supplementary  and I n d i a n  s p a t i a l d i s t r i b u t i o n s of  1.1(b)  slice  data from  been supplemented  oxygen  occur.  Figure  many i n s t a n c e s ,  the major  and  basic understanding  Inlet  I n d i a n Arm w a t e r s  vertical  longitudinal  Burrard  documentation  sections incorporate  34 and 39 ( s e e west  about  this  salinity,  stations  c y c l e s a c h r o n o l o g i c a l sequence of  s e c t i o n s through  exercise  sections at f i v e  in temperature,  Given  longitudinal to  time-depth  Sections)  s y s t e m and has s u g g e s t e d  these changes.  nature  (Vertical  are  the  72 Three l i n e types lines  were  used f o r  sufficient stations contour  were employed  standard  d a t a were  in contouring  i s o p l e t h s common t o  a v a i l a b l e to  a r e as  Burrard  Temperature  Inlet  1.0°/oo  (cr)  Oxygen  In  of  Dashed  strong  gradient,  where major e x t r a p o l a t i o n  were d a s h e d , 24 a n d 3 4 . contours, winter, Indian ment  In  Finally,  dotted  lines  values  cases)  structure  bracketed.  sometimes  was Inlet  from s t a t i o n s for  deleted.  isopleths  in Burrard  Van  11,  supplementary  structure. near the  p r e s e n t e d on t h e  cases)  interpolation  isopleths  illustrate fine  cases)  ml/1 detail)  standard  surface temperatures  information are  portions of  were employed  complicated temperature  contoured  such quoted  for  c o n t o u r s were  d a t a were a v a i l a b l e o n l y  Arm n e c e s s i t a t e d t h a t  the  alternate  a l l oxygen  used o c c a s i o n a l l y to  the  between  Arm  ml/1 o r 0 . 2 on r e q u i r e d  was n e c e s s a r y o r w h e r e  particular,  as o x y g e n  where  Standard  0 . 5 ° C above 8 . 0 ° C 0 . 1 ° C below 8 . 0 ° C 7.5 C i n exceptional  0.4 (dependent  l i n e s were employed  questionable.  was r e q u i r e d .  1.0 below 21.0 0 . 1 above 21.0 (above 21.5 i n e x c e p t i o n a l  0 . 5 ml/1  regions  sections,  1 . 0 ° / o o below 2 7 . 0 ° / o o 0 . 1 ° / o o above 2 7 . 0 ° / o o (above 2 7 . 5 /oo i n e x c e p t i o n a l  1.0  f  Solid  interpolation  Indian  (below  Density  sections.  follows:  0.5°C  Salinity  all  allow confident  o r where o n l y minor e x t r a p o l a t i o n intervals  the  In  late  surface  be q u o t e d ,  vertical  to  in supple-  sections:  The Table  d i s t r i b u t i o n o f c r u i s e s i n t i m e was e a r l i e r p r e s e n t e d  2.1.  interval  As c o n d i t i o n s  a t times changed o n l y  s p a n n e d by t w o . o r e v e n  three  present  vertical  Rather,  selected sets of sections  and o x y g e n major  conditions  Comments  have  ( i . e . temperature,  have  periods, without  figures.  As deep w a t e r  interest,  a l l available sections for this  generally with  May 1 4 ,  1974  t h e i r accompanying  Burrard  When t h e s u r v e y were o b s e r v e d salinities generally As  Inlet  Inlet  principally  included density  time,  o f deep w a t e r  The  particular  been  through  being  uniform,  but s t i l l  throughout  being  the water  column.  d e n s i t y was c o n t r o l l e d  thus  e x p l a i n i n g the s i m i l a r i t y  (The i m p o r t a n c e  of mixing through  of the 8 . 0 ° isotherm at the F i r s t  the moderation  conditions  of the  in late winter,  in  exchanges).  a c c o m p a n i e d by t h e u p t u r n i n g illustrates  Inlet.  (d))  First  c a n be s e e n p a r t i c u l a r l y f r o m t h e t e m p e r a t u r e  downturning  the  presented,  late winter  be more p r o n o u n c e d  Some a s p e c t s o f t h e e f f e c t s Narrows  area,  and s a l i n i t y s e c t i o n s . sections will  Arm a r e o f  maxima  being abundant  the case f o r t h i s  presenting  temperatures  from w i n t e r  by s a l i n i t y a t t h i s  density  discussions  and oxygen  with  concerning  actually  for Burrard  5.14(a)  o^,  illustrate  inserted  a r e a have  figures  (Figures  b e g i n n i n g t o drop high,  i n Indian  commenced i n May 1 9 7 4 ,  in Burrard  is generally  between  conditions  to  table.  salinity,  been p r e s e n t e d t o  o c c a s i o n a l l y been  i n the i n t e r v e n i n g  the  c r u i s e s i t has been u n n e c e s s a r y  sections f o r a l l the c r u i s e s l i s t e d i n t h i s  f o r a given c r u i s e )  changes.  minimally over  in  section,  Narrows  of the 9 . 5 ° isotherm a t the  i n temperature  and Second 5.14(a).  sill, surface  r a n g e e x p e r i e n c e d by w a t e r s  74 passing through waters  the Narrows.  become w a r m e r ,  water column. evident  S i m i l a r l y a t Second Narrows  i n the well  m i x e d w a t e r a t Van 3 4 .  input  i n d i c a t i o n o f t h e same m i x i n g phenomenon  section  5.14(b),  isothermal  p a r t i c u l a r l y i n the downturned surface outflow  Generating  The s t e e p d r o p s  isohalines at  sill  further  evidence of mixing near the bottom.  5.14(d)  there  f r o m I n d i a n Arm p r o v i d e d  demand b e n e a t h a b o u t Second  While  o f oxygen  rich  Again  surface water  10 m o b s c u r e d a n y m a j o r  Inlet  (no s e c t i o n s  the s t r u c t u r e of contours  illustrated  above  i n t h e oxygen Narrows,  section  but  coupled with  oxygen at  presented)  i n J u n e was s i m i l a r  to 1 . 0 ° / o o .  d r o p p e d by a b o u t First  salinity  to  that  f o r May, a d e f i n i t e warming and f r e s h e n i n g o f w a t e r s  a l l d e p t h s was n o t e d .  inside  provide  i n d i c a t i o n of mixing  Temperatures  a t depths  i n c r e a s e d by g e n e r a l l y 1 ° t o 2 ° w h i l e s a l i n i t i e s 0.5  the e f f e c t s  Narrows.  J u n e 2 5 , 1974 B u r r a r d  at  however,  i s minor i n d i c a t i o n of mixing at F i r s t  I n d i a n Arm o u t f l o w  First  i n t h e 2 5 . 0 ° / o o i s o h a l i n e and i n t h e  2 0 . 0 . i s o p y c n a l o v e r t h e Second Narrows  the  Station.  i s seen i n the s a l i n i t y  l o w s a l i n i t y w a t e r a t t h e s u r f a c e , t h u s m a s k i n g somewhat of mixing.  the  t u r b u l e n t motion nearer the head,  from t h e B u r r a r d Thermal  A t Second Narrows,  range through  An i n c r e a s e d t h e r m a l  Similar  Narrows.  deeper  a moderating trend i s  showing the approach toward  g r a d i e n t n e a r Van 39 r e f l e c t s l e s s and p o s s i b l y h e a t  become c o o l e r ;  thus decreasing the temperature  from the s e c t i o n ,  conditions  Surface waters  In t h e a p p r o a c h e s , oxygen 20% w h i l e l i t t l e  Narrows.  d r o p p e d by  concentrations at  10 m  approximately depth  c h a n g e was r e c o r d e d i n o x y g e n  Near-surface  w e r e much s t r o n g e r t h a n  g r e a t e r than  g r a d i e n t s o f both  values  t e m p e r a t u r e and  i n the p r e c e d i n g month.  75 July  17,  1974 B u r r a r d  Mid-July water  Inlet  temperatures  (Figures  5.15(a)  through  t o be a v e r y  First  Narrows.  unusual  In intense  be s e e n f r o m l a t e r  i n s i d e and o u t s i d e F i r s t  a t Van 24 w e r e n e a r l y 0 . 5 ° h i g h e r t h a n  depths exceeding  Maximum  e v i d e n c e was s e e n h e r e o f  In what w i l l  the  o c c u r r e n c e , t h e 9 . 5 ° i s o t h e r m was o b s e r v e d  almost i d e n t i c a l l e v e l s both temperatures  continued to climb.  e x c e e d i n g 1 5 ° C w e r e r e c o r d e d a t Van 3 9 .  c o n t r a s t t o t h e May s e c t i o n , l i t t l e mixing  (d))  showed i n c r e a s e d w a r m i n g t h r o u g h o u t  c o l u m n a s summer a i r t e m p e r a t u r e s  surface temperatures  through  15 m o u t s i d e  the Narrows.  Narrows.  sections at Typically,  those at corresponding  The J u l y  observations  s u g g e s t the r e c e n t e a s t w a r d passage o f a volume o f m i d - d e p t h w a t e r the  sill,  with very  temperatures indicate of  that  little  a c r o s s Second Narrows.  Here,  20 m b e t w e e n  i n t e n s e downward m i x i n g o f warm  features at  Shoal,  example o f m i x i n g  dropped approximately  The  (see Figure  i s s e e n on t e m p e r a t u r e  absence of 29°/oo water  section  the l e v e l of the 1 0 . 5 ° isotherm  s t a t i o n s Van 27 and 3 4 ,  evidence  water.  corresponding s a l i n i t y section 5.15(b) to those j u s t  1.1(b)).  illustrates similar  described, with the 28°/oo i s o h a l i n e appearing  a l m o s t i d e n t i c a l l e v e l s i n s i d e and o u t s i d e F i r s t  15 m d r o p  isotherm)  t h e above d e s c r i b e d exchange d i d n o t cause d i s p l a c e m e n t  the bottom water o f f Burnaby  5.15(a)  The warmer  a t d e p t h a t Van 24 ( n o t e t h e a b s e n c e o f a 9 °  A more t y p i c a l  of  m o d i f i c a t i o n due t o m i x i n g .  over  a t d e p t h a t Van 2 4 , and w i t h  Narrows, an  with  approximate  i n t h e p o s i t i o n o f t h e 2 4 ° / o o i s o h a l i n e a c r o s s Second  In a b s o l u t e t e r m s ,  salinities  werelower  a t a l l depths  the  in July  Narrows. than  in  May,  but were s i m i l a r  in June. strong  July  at depth o u t s i d e F i r s t  salinities  Narrows,  to those  were p a r t i c u l a r l y low near the  recorded  surface,  h a l o c l i n e s b e i n g o b s e r v e d i n t h e top few m e t r e s both n e a r  mouth and n e a r t h e h e a d o f  the  with the  inlet.  Oxygen v a l u e s r e m a i n e d h i g h n e a r t h e s u r f a c e , w h i l e a s l i g h t i n c r e a s e o v e r J u n e v a l u e s was n o t e d a t m i d - d e p t h a t Van 1 1 . presence of water at  h a v i n g oxygen  20 m d e p t h a t Van 2 4 ,  the Narrows  a t s t a t i o n s Van 1 1 ,  and t h e  oxygen  First  and s a l i n i t y o b s e r v a t i o n s a t oxygen  24 a n d 3 4 .  Narrows  sill,  even though  i t was n o t d e t e c t e d ;  27,  1974  Burrard Inlet I n d i a n Arm  (Figures  (Figures  5.16(a)  5.17(a)  t h i s l a t e August  cruise  f r o m summer t o w i n t e r  for  only than 11  however,  value.  through  through  p a s s e d t h e t i m e o f maximum t e m p e r a t u r e  late July,  (less  c o n c e n t r a t i o n may h a v e b e e n p r e s e n t b e t w e e n Van  August  transition  outside  this location.  Water w i t h t h e a p p r o p r i a t e  demand c o u l d a l s o e x p l a i n t h i s l o w e r  in  ml/1  c o n c e n t r a t i o n s were d e t e r m i n e d  oxygen  Having  than 4 . 5  w i t h no s u c h l o w v a l u e s b e i n g r e c o r d e d  m u s t be remembered t h a t  4 . 5 ml/1)  less  need n o t d i s c r e d i t t h e e x p l a n a t i o n e a r l i e r p r e s e n t e d  anomalous t e m p e r a t u r e It  concentrations of  The  (d))  (d)) and minimum s a l i n i t y  i l l u s t r a t e d t h e commencement  conditions.  It  was a l s o t h e  of  cruise  o n w h i c h s e c o n d a r y s a m p l i n g i n I n d i a n Arm was i n i t i a t e d .  The  Burrard Inlet  temperature  s e c t i o n p o r t r a y s what i s becoming a  r e c o g n i z a b l e p a t t e r n w i t h a degree of mixing e v i d e n t and s u b s t a n t i a l m i x i n g e v i d e n t a c r o s s Second N a r r o w s . higher at depth depth..  inside First  Narrows  than  in July  across F i r s t  Narrows  Temperatures  but at g r e a t e r  were  than  10  77 o u t s i d e the Narrows,  temperatures  had b e g u n t o  fall.  R e s p o n d i n g t o d e c r e a s e s i n r u n o f f and i n p r e c i p i t a t i o n s i n c e salinity little at  increased at a l l depths.  i n d i c a t i o n of  Van 3 4 ,  recorded  a fact  On t h i s A u g u s t  s i g n i f i c a n t f r e s h water  consistent with  i n t h i s month.  section there  outflow  low r u n o f f v a l u e s  Oxygen v a l u e s t h r o u g h o u t  dropped s i n c e the previous c r u i s e ,  is  from Indian (Figures  Arm  4.2(b))  the e n t i r e  r e f l e c t i n g a decrease in  July,  inlet biological  p r o d u c t i o n o r p o s s i b l y a c o n t i n u a t i o n i n o x y g e n demand away f r o m  the  surface.  The f i r s t presented in  i l l u s t r a t i o n of  in Figure  the temperature  less  than  water  from Burrard  Inlet  d e p t h a t Van 3 4 . and t h e 4 m l / 1  of year.  extent At  The  section.  15 t o 20 m.  temperatures  vertical  5.17.  summer c o n d i t i o n s i n I n d i a n Arm estuarine circulation  Outflow appears to  South of  i n excess of  Ind  2,  11°C  is clearly  i s o p l e t h of  i d e n t i f y water r e c e n t l y  all  i l l u s t r a t e the  ( a b o u t 50 m) o f d i r e c t e s t u a r i n e e x c h a n g e a t t h i s  g r e a t e r than  100 m d e p t h ,  recorded ranges  in  section.  by t h e o x y g e n  At  well  d e p t h s e x c e e d i n g a b o u t 70  concentrations decreased uniformly at a l l points o f d e t r i t a l m a t e r i a l must have l e d t o t h e  i n the  depth.  m,  fjord.  l>ow c o n c e n t r a t i o n s  w h i l e downwards m i x i n g o f w a t e r n e a r 50 m f r o m o u t s i d e t h e s i l l decreasing concentrations with  time  temperature  illustrated  account f o r  sill  approximate  The q u i e t c o n d i t i o n s a t d e p t h a r e  Oxidation  intruded  = 20 i s o p y c n a l ,  and s a l i n i t y were s m a l l .  oxygen  depths  a t d e p t h s b e t w e e n 20 a n d 50 m,  26°/oo i s o h a l i n e , the  oxygen  evident  be r e s t r i c t e d t o  where s u c h t e m p e r a t u r e s were r e c o r d e d near S i m i l a r l y , the  is  must  78 September  26,  1974  Burrard  Through September, continued to  October 16,  1974  The  Burrard  Inlet  throughout  20.7  (no s e c t i o n s  (Figures  was o b s e r v e d t h r o u g h o u t  at  salinities 50 m  presented)  5.18(a)  Burrard  through  Inlet  (d))  and i n c r e a s e i n  in October.  t h i s s t a t i o n v a r i e d from 19.4  at  the  Oxygen ml/I surface  50 m.  W h i l e t h e c o n d i t i o n s i n I n d i a n Arm i n O c t o b e r w e r e s i m i l a r described for August,  m i n o r changes were n o t e d .  l a y e r was i n d i c a t e d i n t h e t e m p e r a t u r e extending  s e a w a r d a t 20 m d e p t h n e a r  Salinities  data,  Ind  a t depths s h a l l o w e r than about  2.8  5 m i n October.  by a p p r o x i m a t e l y with  Salinities  0.1°/oo.  a s was a c o l d at the  50 t o  approximate  55 m ) .  The  the  inlet.  f r o m 65 m i n A u g u s t  to  had d e c r e a s e d ,  The O c t o b e r d e n s i t y s e c t i o n ,  in conjunction  t h e Van 34 s u g g e s t s a s l i g h t l y  i n l e t and I n d i a n Arm t h a n was i n d i c a t e d i n A u g u s t ,  versus  tongue  head o f  g r e a t e r v e r t i c a l e x c u r s i o n of waters exchanging across the the  those  An i n f l o w i n g s u b s u r f a c e  i n t h e deep w a t e r  the above quoted d e n s i t y d a t a f o r  to  100 m had i n c r e a s e d  c o n s i d e r a b l y w i t h the 26°/oo i s o h a l i n e r i s i n g about  11,  inlet.  t h e w a t e r c o l u m n a t Van 34 w e r e n e a r 4 . 3  w h i l e v a l u e s o f o^. a t to  elsewhere i n the  expected seasonal decrease in temperature  salinity values  presented)  i n c r e a s e d n e a r t h e s u r f a c e a t Van  values to August,  I n d i a n Arm The  sections  f i r s t 3 0 ° / o o w a t e r was o b s e r v e d a t  Oxygen v a l u e s  but m a i n t a i n e d s i m i l a r  (no  t e m p e r a t u r e s d r o p p e d s l i g h t l y , and  increase.  d e p t h a t Van 11.  Inlet  sill  between  (65 t o 70 m  secondary 20.5 isopycnal i d e n t i f i e s  the  depth to which Burrard I n l e t waters would appear to  have  penetrated  by O c t o b e r ,  circulation. Van 34 i t settled  as t h e s u b s u r f a c e component o f  With the presence of  d e n s i t i e s up t o  seems p o s s i b l e t h a t w a t e r s  t o depths even g r e a t e r  crossing  the  20.7  the s i l l  t h a n 70 m i n s i d e t h e  at  5.18(d).  t h a n 4 . 5 ml/1 section,  As o x y g e n  t h e 4 . 0 ml/1  Arm.  earlier that  as oxygen  boundary  of  oxygen  time even a f t e r  decreases of  oxygen  it  is  only a brief  the order of  0.5 to  concentration  r e s i d e n c e i n the Arm. 1.0  ml/1  and f o r  intruding waters  w o u l d be a c c e p t a b l e .  the  1.2  105 m i n O c t o b e r . ml/1,  November 7 ,  ml/1  It  i s to  Allowing  the e f f e c t s  b a s e d upon  The A u g u s t  1974  Burrard  developed  in Burrard  it  Inlet  I n d i a n Arm By e a r l y N o v e m b e r ,  c o n c e n t r a t i o n a t 200 m a t had d r o p p e d t o 0 . 7 9  (Figures  (Figures  5.19(a)  5.20(a)  that  Temperatures  Salinities  through  near  2 was  (d))  (d))  uniformity  were g e n e r a l l y  and 1 0 . 0 ° C , w i t h s l i g h t l y w a r m e r w a t e r  to  levels.  ml/1.  through  the c h a r a c t e r i s t i c winter  Inlet.  Ind  of  density  be n o t e d a s w e l l  i s o p l e t h r o s e f r o m 130 m i n A u g u s t  w h i l e in October  Inlet  likely  c o n c e n t r a t i o n s at depth continued to decrease from August  The d e p t h o f  Van 3 9 .  inlet  intruding Burrard  i d e n t i f i e d a s a month o f maximum c o n s u m p t i o n ,  considerations,  9.3°  the  greater  i s n o n - c o n s e r v a t i v e and a s O c t o b e r was  mixing the e a r l i e r d e s c r i p t i o n of  1.06  i s o p l e t h of  i n t r u d i n g w a t e r s would e x p e r i e n c e a d e c r e a s e i n oxygen  at t h i s for  However,  oxygen  t o 50 m d e p t h and o n l y h a l f way up t h e  w o u l d a p p e a r t o mark an a p p r o x i m a t e waters.  have  v a l u e s a t Van 34 w e r e c o n t i n u a l l y  up t o t h i s t i m e ,  extending only  50 m a t  could  S u c h h y p o t h e s e s a r e n o t o b v i o u s l y s u p p o r t e d by t h e section  estuarine  had  between  being observed  near  w e r e g e n e r a l l y h i g h and p a r t i c u l a r l y i n s i d e  First  80 Narrows  were u n i f o r m .  40 m d e p t h .  Values  A minor f r e s h e n i n g r e s u l t of The of  First  from  the  were between  the  surface to  b e i n g between  4.0  14  2 6 . 0 and  s u r f a c e n e a r Van  17  at 28.5°/oo.  as a  watershed.  nearly  vertical,  50 m.  Finally,  and 4 . 5 m l / 1  November s a l i n i t y and d e n s i t y  evidence  of  range  salinities  of  intense mixing  1 . 5 ° / o o a t Van 2 4 . to a range of observed  with  changes  oxygen  at a l l  values  points  at  sill  effects  further  through  This  depth  First  at  was f u r t h e r Water  (14  east  of  having  through  (diffusion,  i n terms 15  of  but  of  inflow.  f r e s h e n i n g due t o  an e s t u a r i n e c i r c u l a t i o n w i t h  source waters property  properties  at  i n t h e v i c i n i t y o f Van 3 4 .  was r e c o r d e d a t g r e a t e r  than  Such  of  in  explicit  oxygen  consumption  surface outflow  in  In p a r t i c u l a r ,  Indian  No u n u s u a l  about  Narrows  observation  changes  ascribed to in  the  pronounced  the J u l y  property  inflow.  these depths  Narrows  24.  runoff,  r a n g e 20 t o 70 m w e r e r e a d i l y  Water  of  of  2 9 . 0 ° / o o was  some number  t o 20 m a c c o m p a n i e d by m i d - d e p t h  in the depth  all  Second  a range  passage through  nature  October d a t a ,  A  was r e d u c e d t o  28.56°/oo.  a n d a t Van  I n d i a n Arm w e r e e x p l i c a b l e i n t e r m s processes  17,  the anomalous  s i m i l a r w a t e r m a s s e s a t Van 17  17  a s a l i n i t y of  m) a t Van  continued  and S e c o n d N a r r o w s .  reduced through  50 m a t Van 24 t o  emphasize  In the August  sections provide  e x c e e d i n g 6 ° / o o a t Van  0.4°/oo.  reduced s a l i n i t i e s  top  t o Van  Narrows.  The  or  had p r o g r e s s e d  Narrows  e f f e c t was n o t e d a t  in  too were u n i f o r m ,  of  east of  p r o f i l e a t Van 34 was v e r y  0.22  Second  30°/oo water  h i g h November r u n o f f f r o m t h e C a p i l a n o R i v e r  density only  The  this  75 m d e p t h .  the changes  estuarine  Arm m a t c h e d change  etc.)  in  those any  of  However,in the i n t e r v a l in water readily waters  properties  i n terms  of  in  terms  As  of  this  ambient  Ind  1.3  November c o n d i t i o n s a t Van  at  Ind Ind  1.5,  t h e maximum v a l u e  1.3.  p r o c e s s e s can a c c o u n t f o r  up-inlet  i n the  by t h e  at  contours  mid-depth  150 m)  data.  well  towards  the  it  c a n be  concluded Inlet.  contours,  head,  than  Ind  60 m n e a r  i n t r u s i o n of  This  toward  indications  150 m d e p t h  near  situ  the  Tongue-like  The  The  the  head,  effectively  activity  2.8  the  of  range.  towards  150 m i n d i c a t e s m i n i m a l  greater  than  recorded  and as no i n  i n the d i s p l a c e d waters.  minor d i s r u p t i o n at depths  extending  50 t o  at  27.34°/oo  i s o h a l i n e s are  i n the  l e v e l , w h i l e the downturning  (shallower  interpretation  Arm f r o m B u r r a r d  i n f l e c t i o n s i n these  2 7 . 2 ° / o o contour  and  increase  100 m d e p t h  intruding waters.  and 2 7 . 1 ° / o o  i n d i c a t e upward m o t i o n  horizontal this  shallower  i s the  salinity distribution further  displacement of waters  successively also  27.2  being  such changes, Indian  head w h i c h a l s o shows e v i d e n c e o f structures  it  i n oxygen  34.  (Figure 5.18(b))  have e n t e r e d  i s supported  resident  As no s u c h h i g h s a l i n i t i e s w e r e  physical  t h i s w a t e r must  cannot  s a l i n i t y section 5.20(b) s a l i n i t i e s  i n t h e Arm i n O c t o b e r  conclusion  1.3,  l o c a t i o n and d e p t h w h i c h d i s a l l o w s  anywhere  that  Ind  2 7 . 3 ° / o o w e r e r e c o r d e d on November 7 a t and  (o-j. = 2 1 . 0 3 )  at  occurred  Arm w h i c h  e s t u a r i n e exchange w i t h  100 m d e p t h  i s i l l u s t r a t e d by t h e  excess of  Indian  W h i l e changes were e v i d e n t  d i s t r i b u t i o n s at  s a l i n i t y at  16 t o November 7 c h a n g e s  e x c e e d i n g 70 m i n  i n s i d e Second Narrows.  in  both  a t depths  be e x p l a i n e d  temperature  in  October  suggest  head.  high s a l i n i t y  below only  Thus a water,  i s i n d i c a t e d by t h e November s a l i n i t y  82 A less is  pronounced  i n f e r r e d from the  with  oxygen  of  The  observations, again with  horizontal  0 . 8 ml/1  (100  rising,  up-inlet  absence of  oxygen  the  depth  m versus  of  i s o p l e t h , of  85 m ) .  as e v i d e n c e o f d i f f e r i n g  evidence of  the  the core of  about  Temperature  contours  data  a major  the  oxygen  level  than  provide  150 m.  the  Finally  observation  upswing  of  north  intrusion.  of  Ind  up-inlet  off. the A apparently  salinity explained depths.  inconclusive tilt  than  of  shows  100 m b e i n g  i n November, stabilize.  the  section  October s e c t i o n  2 i s most  on  at d i f f e r e n t  the d e n s i t y  greater  i l l u s t r a t e d by t h e  isopycnal  rather  by  3 in  based  i n d i c a t i o n by  consumption  a n d c o n d i t i o n s had had a m p l e t i m e t o  the  but  a s i n d i c a t e d by  ceased,  flow associated with  head,  Ind  i s the  excepting  at the time of  21.0  at  S u c h d i s c r e p a n c y may p o s s i b l y be of  the  further  and s a l i n i t y d a t a  intruded water  rates  1.3,  section  150 m.  i d e n t i c a l to  the  the  i s the  almost  suggests that  head a r e  h e r e shown t o  c o n d i t i o n s with d e n s i t i e s at depths  This  Ind  i s a d i s r u p t i o n of  observations  stable  those  at  below about  (Figure 5.20(a))  less  pocket  f l o w a s was s u g g e s t e d  no m o t i o n  oxygen  intrusion,  at depths  are  the s a l i n i t y data  c o n f l i c t between  isotherms  3 . 8 ml/1  in a s p e c u l a t i v e p i c t u r e at  Consistent  greater  The  intrusion  i l l u s t r a t e d by t h e O c t o b e r o x y g e n  a gradually  November r e s u l t s  possible  section 5.20(d).  exceeding  pattern  s a l i n i t y data.  salinity  oxygen  c o n c l u s i v e i n d i c a t i o n of  Oxygen i s o p l e t h s s l o p i n g t o w a r d  indication the  still  concentration  e s t u a r i n e exchange (5.19(d)).  but  5.18(c).  inflow  The  had  minor  likely a result  of  83 Waters cruise  r e s i d e n t i n s i d e Second Narrows  had s a l i n i t i e s  (maximum 2 0 . 8 9 a t core of waters  (maximum  Ind  o b s e r v e d i n s i d e Second Narrows  intruded to  west of  100 m d e p t h  the  time of  40 m a t Van 3 4 )  1.3  following  the p e r i o d of  on t h e p r e v i o u s  the  i n October  inflow,  suggested  and i n N o v e m b e r ,  i n the  I n d i a n Arm.  and f u r t h e r  l e v e l s r e c o r d e d on November  7.  from  t i d e and w i n d c o n d i t i o n s m u s t h a v e p r e v a i l e d s u c h a s  to  of  s u f f i c i e n t d e n s i t y a c r o s s the Second Narrows  of  that  indigenous water at approximately  I n d i a n Arm s i l l  with  i t s density. toward  the  such d i s p l a c e d water  Inspection of  head o f  inlet.  November 7 r e v e a l s t h a t  spring tidal  t h e neap t i d a l  Again dependent  on  water density,  northward.  the p e r i o d October  16  r a n g e s p e a k e d on November  r a n g e minimum o f  period of  in  i n s i d e t h e Arm c o n s i s t e n t  c o u l d r i s e g r a d u a l l y i n i t s passage  t i d e and w i n d d a t a f o r  24-hour  100 m d e p t h  i t would d i s p l a c e i n d i g e n o u s  the  sill  i t must then have p a s s e d  and s e t t l e d t o a l e v e l  In d o i n g s o ,  is  a f t e r m i x i n g t h e r e s u l t i n g d e n s i t y was  In p u r e l y a d e n s i t y d r i v e n f l o w  approximately  evident  34  it  the  (following  that  and November c r u i s e s ,  over  northward,  appropriate  some t i m e b e t w e e n t h e O c t o b e r  f r o m t h e v i c i n i t y o f Van 2 4 , to that  least  and w i n d f o r c i n g c a n be  t r a n s p o r t water  equal  waters  d e n s e w a t e r r e s i d e n t a t d e p t h a t Van the  As  a p r o c e s s b a s e d upon t i d a l  At  that  the  16)  i n I n d i a n Arm had t h e i r o r i g i n a t  T h o u g h t h e m e c h a n i s m by w h i c h s u c h e x c h a n g e o c c u r s i s n o t  postulated.  and d e n s i t i e s  (October  i t m u s t be c o n c l u d e d t h a t  experienced decreases i n density to  the present d a t a ,  November  ( 2 7 . 3 4 ° / o o and 2 1 . 0 3 ° / o o ) .  S e c o n d N a r r o w s w h e r e d e n s i t i e s and s a l i n i t i e s  ranges were o b s e r v e d both  the  w h i c h were l o w e r than t h o s e of  100 m a t  c r u i s e were even l e s s d e n s e , which  2 7 . 1 4 ° / o o at  40 m a t Van 3 4 )  intruded water at  at  October  abnormally strong  24),  and t h a t  to 2 - 3 an  ( 3 3 km/hr d a i l y mean  84 speed) west n o r t h w e s t e r l y plausible  It  that  s u c h c o n d i t i o n s c o u l d have  i n i t i a t e d the  was e a r l i e r i n f e r r e d f r o m t h e d e n s i t y  November 7 ,  the  Second Narrows volume  w i n d s was r e c o r d e d on O c t o b e r  i n t r u s i o n has c e a s e d . m u s t have c o n t i n u e d t o  of dense water  eastward,  most p r o b a b l y account f o r a t Van 3 4 .  it  28.  It  observed  section 5.20(c)  Although  tidal  transport  at  exchange  l e a s t some  downward m i x i n g a t  by w h i c h t h e d e n s i t y  of waters  across  i s suggested that mixing .effects  f r e s h water  Second Narrows  by  small  depth  W i t h t h e November i n c r e a s e s i n p r e c i p i t a t i o n and of  intrusion.  that  the observed decrease i n d e n s i t y at  p r o v i d i n g s u b s t a n t i a l volumes  is  to the s u r f a c e  runoff layer,  i s c o n s i d e r e d a p r o b a b l e mechanism  below s i l l  depth  a t Van 34 c o u l d  have  decreased.  Thus emerges a p i c t u r e o f basin waters,  Salinity though  Burrard  Inlet  in  Van 2 4 .  (no  sections  and d e n s i t y s e c t i o n s from t h i s the  show a d i s t i n c t c o n t r a s t  observations found  1974  (Figure  5.20).  transport  of  In  On November 25 h o w e v e r ,  Arm  waters forcing.  presented) l a t e November  i n magnitudes  that  cruise,  to  waters  l e a s t as f a r west  u n u s u a l l y dense waters  observed  intrusion into  1 . 2 5 ° / o o t o a maximum o f  Inlet  t h e November 7  e a r l i e r i n s t a n c e , dense  I n d i a n Arm w e r e t r a c e d t o a s o u r c e a t  increases of  Indian  previously presented Burrard  Van 24 and a t Van 34 showed no e v i d e n c e o f Salinity  of  and p o s s i b l y a s s i s t e d by w i n d  s i m i l a r in s t r u c t u r e to  sections,  exchange  p r i n c i p a l l y c o n t r o l l e d by t i d a l  from o u t s i d e Second Narrows,  November 2 5 ,  intermittent  the  2 8 . 3 9 ° / o o were  as at  Arm. recorded  85 at  depth a t  1.09,  to a  Van 34 t h r o u g h = 21.98.  t  Within  than  15 m d e p t h  this  being a t t r i b u t e d  dense water  November.  over  Indian Arm,  to dropping below t h a t  by c o n d i t i o n s i n t h e o u t f l o w i n g and r u n o f f  increased supply of volume  to  density  of  of  the  into  to  the  f r o m 30 It  I n d i a n Arm w a t e r . turbulent  the dense water described  December  at  5-6,  December  and  inflow across  no s i g n i f i c a n t  unmodified  I n d i a n Arm s i l l ,  s i m i l a r to  those of  the s u r f a c e o u t f l o w , must e v e n t u a l l y  then  the  volume  the r e t u r n deep  d e p t h t o y i e l d t h e f r e s h e r December  1974  Burrard  Inlet  as t e m p e r a t u r e s  had t e m p e r a t u r e s  The  (Figures  (Figures  i n f l u e n c e of w i n t e r  t h e i r November v a l u e s .  west,  water  flow that  indigenous  and have  continued modified  conditions  below.  Further  Narrows  into  increased  fresher  a t Van 34 p a s s e d  be c o n c l u d e d t h a t  Second Narrows  I n d i a n Arm  in  this  explained  been o b s e r v e d ,  return  c l e a r l y show t h a t  (and d e n s i t i e s )  Entrainment  mixing at  of  November,  The  layer with  had p r e v i o u s l y  50 m d e p t h  must thus  acquired s a l i n i t i e s  is  Through  the s u r f a c e l a y e r .  was s u f f i c i e n t l y m o d i f i e d by m i x i n g a c r o s s t h e it  greater  confinement  I n d i a n Arm s i l l  outflowing  than  The m e a s u r e d s a l i n i t i e s  I n d i a n Arm.  The  surface layer.  f r e s h water  greater depths  the dense water  i n c r e a s e s at  temperatures.  thus r e s t r i c t i n g the c r o s s - s e c t i o n a l area of sill.  i n c r e a s e d by  i n c r e a s e d s u b s t a n t i a l l y , p r o v i d i n g a much  caused a deepening of  penetrating  density  t h e same p e r i o d w e r e a t m o s t an i n s i g n i f i c a n t 0 . 0 5 ,  to depths  precipitation  Likewise,  5.21(a)  5.22(a)  through  through  c o o l i n g was n o t e d  d e c r e a s e d by a b o u t  (d))  (d))  in Burrard  1 ° C a t most d e p t h s  n e a r l y u n i f o r m w a t e r mass i n s i d e  r a n g i n g between  l a c k of m i x i n g near the  Inlet  First  8 . 5 ° and 8 . 9 ° C w h i l e t o  s u r f a c e and t h e r e m n a n t s  of  from  summer  the  86 heating  at  depth maintained  Salinities depth the  sill.  the  the  at depths  r e s t of  the  The  to  i l l u s t r a t e d by t h e  Narrows.  As  conditions intensity  of mixing  Oxygen v a l u e s  system s i n c e e a r l y  By December intrusion  the  of  the  having  and m i x i n g  of  increases.  uniform  was n o t  effects  into  of  Indian  the  34  20.29. First  as  the  evident. the  entire  October-November  Arm w e r e much  s a l i n i t i e s i n excess of the  smoothed.  2 7 . 3 ° / o o which  i n t r u s i o n was no l o n g e r  i s probable  140 m d e p t h  evidence of  p o s s i b i l i t y remains  c o u l d have As  to  c r u i s e , and  throughout  contributed  no a b s o l u t e  modification experienced  to  as w e l l the  that  salinity  northern  i n November t o  to y i e l d a minor (and  c r o s s i n g the v a r i o u s  near  advection  increased additional  density)  c o n c l u s i o n s c a n be d r a w n a s t o t h e  by w a t e r s  had  visible  the mid-depth  t h e s e more s a l i n e i n t r u d i n g w a t e r s The  from  a decrease  1.69  clearly  and  and  Van  i n the v e r t i c a l ,  0 . 5 ml/1  i n l e t from approximately  i n December  salinities.  showing  at  The r i s e i n t h e 2 7 . 2 ° / o o i s o h a l i n e i n t h e  80 m d e p t h  intrusion  initial  the core of  (Figure 5.22(b)). portion  6,  water  e a r l i e r marked  approaches  November.  of mid-depth waters  pocket of  near  m i x i n g was i n t e n s e t h r o u g h  a c r o s s Second Narrows  had i n c r e a s e d by a b o u t  the  of  at  20 m d e p t h  observed  s a m p l e d on t h i s  relatively  Georgia water  decrease in s a l i n i t y  2 6 . 1 9 ° / o o and i n d e n s i t y  s t a t i o n Van 27 was n o t  9.1°C.  high p r e c i p i t a t i o n  new w a t e r s  s a l i n i t y contours,  a t Van 24 w e r e  15 m i n  dense deep w a t e r  l a t e November had b e e n r e p l a c e d , t h e 2 . 2 0 ° / o o to  of  and  now r e s i d e d a t  the e a s t ,  a general  7.6°  Strait  s h a l l o w e r than  inlet  recorded values.  in s a l i n i t y of  The  as 3 0 ° / o o w a t e r  i n November a c c o u n t e d f o r  previously  As  narrows,  However,  throughout  in  between  showed an i n c r e a s e d i n f l u e n c e o f  outside  runoff  temperatures  sills  extent at  a  of  given time, the  the c o n t i n u e d presence of dense water  continued p o s s i b i l i t y of  salinities  intrusion.  d e c r e a s e d by a p p r o x i m a t e l y  i n d i c a t i n g a continuation of head, low  continued high runoff  At  200 m d e p t h  at  Ind  2,  0 . 0 2 ° / o o f r o m November l e v e l s ,  relatively quiet  conditions.  Near  and p r e c i p i t a t i o n a c c o u n t f o r  the  the  observed  salinities.  The  temperature  high temperature  suggestions  of  section 5.22(a)  water  n e a r 60 m d e p t h a t  extending  Ind  1.5,  northward  shows a downward  from about  Nearer  winter  c o o l i n g and s h a l l o w e x c h a n g e w i t h  observed s t r u c t u r e depth,  November  the  (from  temperatures  oxygen  isopleths  At  depth,  i n oxygen Ind  ml/1. of  Inlet  i n the  at  Ind  1.3  Ind  1.5,  suggesting major  later  possibly  to  rising  increased  waters  account  temperature  regime.  0.04°C since  concentration.  at depths  oxygen  as t h e d e p r e s s i o n o f oxygen,  further  the  is  the  through mixing  By December  0 . 5 4 ml/1  and  observed  6 the value  at  200 m  f r o m i t s November 7 v a l u e  s h a l l o w e r than  v a l u e s were  i n f l u e n c e of  intruded water  consumption accounts f o r  2 had d r o p p e d t o Finally,  some d e g r e e o f  or p o s s i b l y of  suggest a c o n t r i b u t i o n of  diffusion.  north  head t o mouth)  section 5.22(d),  o b s e r v e d n e a r 100 m d e p t h  0.70  Burrard  head  earlier  waters,  had i n c r e a s e d a p p r o x i m a t e l y  November i n t r u d e d w a t e r  depth at  surface, cold runoff  the  of  7.  In t h e  decreases  at  advection of mid-depth waters,  the head.  for  s l o p i n g tongue  25 m d e p t h  which i s c o n s i s t e n t with  toward  At  a t Van 24 i m p l i e s  50 m and i n t h e  higher than  in early  i n f l u e n c e by r e c e n t l y e x c h a n g e d B u r r a r d  of  region  November, Inlet  waters.  88 In summary,  t h e December s e c t i o n s g i v e no i n d i c a t i o n t h a t  major exchange o c c u r r e d a t m i d - d e p t h a f t e r salinity  Changes  and d e n s i t y c a n p o s s i b l y be e x p l a i n e d by m i x i n g o f  intruded waters, volume  e a r l y November.  however,  the p o s s i b i l i t y remains t h a t  i n t r u s i o n s c o u l d have t a k e n p l a c e .  affected  by t h e  potential  If  so,  i n t r u d i n g w a t e r s were so s m a l l  effects  of m i x i n g .  and t o  evidence that  entered  moved  e s t u a r i n e e x c h a n g e was t a k i n g p l a c e a t d e p t h s  shallower  1975  At  g r e a t e r than about  i n t r u d i n g waters  Burrard  Inlet  column.  had b e e n  (no s e c t i o n s  125 m d e p t h ,  little  felt.  presented)  Due t o v a r i o u s s h i p and e q u i p m e n t p r o b l e m s on t h i s J a n u a r y stations  Van 2 7 ,  39 and Ind  1.5  vertical it  d a t a were a v a i l a b l e f o r  sections.  the p r e p a r a t i o n of  From p r o f i l e s a t Van 2 4 ,  i s p o s s i b l e , however,  to  identify  basic  As was e v i d e n c e d d u r i n g N o v e m b e r , salinity through  (therefore, December,  but  density)  a l s o took  t h e r e was s t i l l  s a l i n i t y was o b s e r v e d t h r o u g h  with  i n c r e a s e s f r o m December 5 a t  In c o n t r a s t ,  at  60 t o  100 m d e p t h  34 and a t  Consequently,  detailed Ind  0,  1 and 2  conditions.  s i g n i f i c a n t increases in p l a c e a t d e p t h a t s t a t i o n Van  no i n d i c a t i o n o f  e x c h a n g e o f m i d t o deep I n d i a n Arm w a t e r s . in  cruise,  were e x c l u d e d from the s a m p l i n g program.  N e i t h e r was a n y s e c o n d a r y s a m p l i n g c o n d u c t e d i n I n d i a n A r m . insufficient  the  continued  change a s s o c i a t e d w i t h  January 3 ,  small  There i s  t h a n 50 m n e a r t h e m o u t h .  i n the water  previously  a s t o be m a s k e d by  have  in  changes  I n a n y e v e n t w a t e r s w h i c h had  have r i s e n  the  further  property  and s e t t l e d n e a r 100 m d e p t h on November 7 a p p e a r t o northward,  further  further  An a p p r o x i m a t e  the harbour e a s t of  Second  major  l°/oo increase Narrows,  5 0 m a t Van 34 b e i n g 1 . 2 9 ° / o o . in  Indian Arm,  salinity  34  89 decreases  of  up t o 0 . 2 ° / o o w e r e r e c o r d e d , i n d i c a t i n g an a b s e n c e  recent mid-depth exchange. begun t o d e c l i n e ,  By J a n u a r y ,  p r e c i p i t a t i o n and r u n o f f  w i t h the consequent weakening of  I n d i a n Arm.  At  depth,  oxygen  continued to  indicate quiet  concentrations of  23,  1975  Burrard Inlet I n d i a n Arm  The J a n u a r y of air  the trends  (Figures  (Figures  23 s e c t i o n s f o r  5.23(a)  Burrard  about  0.5  through  through  Inlet  of  both  of waters  First  (d))  Further  lower water  evolution  decreases in  temperatures,  t h e s y s t e m b e i n g b e t w e e n 7 . 5 ° and 8 . 0 ° C .  i n the  and S e c o n d N a r r o w s ,  inner basins.  10 m d e p t h a t Van 34 f o r a t Van 3 4 , evident,  the f r e s h e n i n g i n f l u e n c e of  though  salinity,  t h e d e n s i t y s e c t i o n shows a  The  increase throughout  f r o m December  Within January  3.  the  i n c r e a s i n g the  the  salinity  2 7 ° / o o were r e c o r d e d study.  Near the  I n d i a n Arm o u t f l o w was i n December.  v a l u e s b e t w e e n 21  at  surface  still  Paralleling and 22  at  these being the highest d e n s i t i e s  observed i n s i d e Second Narrows.  a further  t  of  i n the  i n a shallower l a y e r than  g r e a t e r t h a n 15 m d e p t h a t Van 3 4 , yet  thereby  Salinities  the f i r s t time  there  (d))  h i g h s a l i n i t y w a t e r s from the approaches c o n t i n u e d to mix a c r o s s sills  from  ml/1  show f u r t h e r  3 data.  w e r e a c c o m p a n i e d by s t i l l  with values throughout  surface outflow  3.  5.24(a)  i d e n t i f i e d i n the January  temperature  had  conditions, d e f i n i t e l y confirming that  had b e e n no m a j o r e x c h a n g e b e f o r e J a n u a r y  January  of  Finally,  harbour of  the oxygen  s e c t i o n shows  approximately  0.5  ml/1  values.  Indian Arm,  a major f l u s h i n g event  While temperature,  had commenced  since  s a l i n i t y and d e n s i t y c h a n g e s a s s o c i a t e d  90 w i t h the  i n t r u s i o n were s m a l l  (yet  m e a s u r e a b l e ) , oxygen  c h a n g e d by up t o 800% t h u s p r o v i d i n g a m o s t v i v i d exchange and o v e r t u r n . oxygen  r i c h waters  displacing  From t h e o x y g e n  had p e n e t r a t e d  i n d i c a t o r of  section 5.24(d)  it  50 t o  Indian  u p w a r d s and t o w a r d  100 m d e p t h n o r t h o f  the  i s seen  t h e e n t i r e deep b a s i n o f  i n d i g e n o u s low oxygen w a t e r s  The o x y g e n minimum r e c o r d e d a t  concentrations  the  Ind 2 . 8  p r e v i o u s l y r e s i d e n t at g r e a t e r than  180 m d e p t h  the f j o r d .  distribution isopleths  c e n t r e of  of oxygen,  appears that  a n g l i n g downwards  from the v i c i n i t y of intruded waters the n o r t h .  it  Ind  such a boundary  i n t h e deep w a t e r w e r e l e s s  the source water mixing,  of  Even i n c r o s s i n g  oxygen  the s i l l  oxygen  near Ind  l o w e r oxygen  outflowing  surface.  section  5.24(d)  that  0,  the o l d  s u r f a c e l a y e r and t h a t  to depths  less  than about  Arm.  remainder of  waters.  110  terms,  I n d i a n Arm w a t e r  m i n the  that  values  the inlet.  at depth  were  low oxygen it  in  Such  the e n t i r e  however,  had  oxygen  5 . 0 and 5 . 5 m l / 1 .  throughout  to  there  w h i l e oxygen  c o n t e n t by m i x i n g w i t h  t h e Arm i n t h e  The  Obviously  intruding waters  In g e n e r a l  some o f  the  c o n c e n t r a t i o n makes  i n t r u s i o n , as  t h a n 4 . 6 ml/1  extremes  being modified to at the  between  c o n t i n u e d consumption must a c c o u n t f o r  observed moderation of  ml/1  5.24(d))  boundary  difficult.  a t Van 34 r a n g e d b e t w e e n  coupled with  about  i n d i g e n o u s I n d i a n Arm w a t e r s  been c o n s i d e r a b l e m i x i n g a s s o c i a t e d w i t h t h e values  on  December  and 3 . 6  (on F i g u r e  1 mark an a p p r o x i m a t e  The n o n - c o n s e r v a t i v e n a t u r e of  t h e 3 . 2 ml/1  t o w a r d t h e head  t o t h e s o u t h and t h e  a clear definition  B a s e d upon t h e  Arm,  head.  J a n u a r y 23 i d e n t i f i e s w a t e r s i n the  that  waters  is clear  had a l r e a d y  from left  w h i c h r e m a i n e d was r e s t r i c t e d  n o r t h and c e n t r a l  reaches of  t h e b a s i n was now o c c u p i e d by r e c e n t l y  the  intruded  91 Although  such d e t a i l  t h e Arm i s n o t inferences  as t o t h e d i s t r i b u t i o n o f  as c l e a r f r o m t h e o t h e r  c a n be d r a w n t o s u p p o r t  the 7 . 9 ° to 7 . 8 °  i s o t h e r m s between  sections in the s e t ,  the above Ind  1.3  conclusion.  and Ind  o f w a t e r s f l o w i n g down t h e s o u t h e r n s l o p e o f pointing  tongues  the o u t f l o w i n g  abundance o f w a t e r confirmation of near the of  the  intrusion.  Higher  that waters  had p e n e t r a t e d t o  boundary  to s u r f a c e o u t f l o w ,  isohaline  horizontal  i s evidence of  comments a p p l y t o  In c o n t r a s t t o  the  mid-depth  which allows  sill  I n d i a n Arm.  d e p t h a t Van  0 . 1 0 ° / o o from e a r l y  w h i l e t h e s l o p e n e a r Ind  as the  January  1 i n the  as w e l l .  = 21.25  27.2°/oo  Similar  the  (and  sill.  November i n t r u s i o n , when s o u r c e w a t e r s Second N a r r o w s ,  i n f l o w of waters  this  from the  January vicinity  From c o n d i t i o n s o b s e r v e d s i m u l t a n e o u s l y i n B u r r a r d the  lower  isopycnal  i s o p y c n a l ) are continuous over  the October -  34  Absolute increases  i n t r u s i o n near t h i s l e v e l  = 21.3  water  confident  2 7 . 1 ° / o o i s o h a l i n e m a r k s an a p p r o x i m a t e  e v e n t was c l e a r l y a d e n s i t y d r i v e n  that  at  I n d i a n Arm d e e p  I n d i a n Arm s i l l ,  were i d e n t i f i e d as e x i s t i n g o n l y west o f  Van 3 4 .  further  probably  the d e n s i t y s e c t i o n ,  most p r o b a b l y the  the  t h e 2 7 . 2 ° / o o i s o h a l i n e (and most  the deeper p a r t s of  The  identify  salinity  from approximately  values.  southward  i n t e r e s t on t h e  s a l i n i t y a t d e p t h were i n the range o f  clear  100 m d e p t h ,  than 7 . 8 ° C i s  of  in  give indication  temperature waters  The p r i m e f e a t u r e  i s the c o n t i n u i t y of  interpretation  of  than  less  Tongues  s e c t i o n again  head a r e a g a i n i n t e r p r e t e d a s b e i n g t h e  the 2 7 . 3 ° / o o i s o h a l i n e ) over  in  greater  having temperatures  t h e December c r u i s e .  section  At  1.5  in  various  the i n l e t , w h i l e  a b o v e 20 m on t h e t e m p e r a t u r e  surface layer.  intruded waters  l a t e J a n u a r y o b s e r v a t i o n s were o f  Inlet  a dynamic p r o c e s s .  it  is  92 The  overturn  c a u s e d by t h e  i n t r u s i o n had c l e a r l y n o t  The  i n t r u s i o n i t s e l f may have b e e n o n g o i n g a t  the  stabalized.  time of  the January  23  cruise.  February  19-21,  1975  Burrard Inlet I n d i a n Arm  (Figures  (Figures  5.25(a)  5.26(a)  through(d))  through  (d))  Rather minimal changes were r e c o r d e d i n c o n d i t i o n s i n Inlet  d u r i n g t h e f i r s t weeks o f  amount v a r y i n g f r o m 0 . 5 ° t o Salinities  February.  1.0°C, marginally increasing density.  by a p p r o x i m a t e l y  a g a i n c a u s i n g an i n c r e a s e i n o ^ .  of  in January  Second Narrows  to 21.60  low oxygen w a t e r , the form of  of  c o n t o u r s on t h e  the  (at)  in February.  sill  depth  rose  Oxygen c o n c e n t r a t i o n s w e s t  0 . 5 ml/1 t o n e a r l y 6 . 0 m l / 1 , associated with  outflow  W h i l e v a l u e s changed as i n d i c a t e d  t h e d i s t r i b u t i o n s changed l i t t l e , February  sill  g r e a t e r than 2 7 . 5 ° / o o ,  values at  about 4 . 5 ml/1, l i k e l y  were r e c o r d e d .  above,  0 . 2 ° / o o to  Density  r o s e by a f u r t h e r  w h i l e n e a r Van 34 v a l u e s o f of  d e c r e a s e d by an  increased only s l i g h t l y , w i t h the s a l i n i t y of water at  d e p t h a t Van 34 r i s i n g  from 21.40  Temperatures  Burrard  with the  shapes  s e c t i o n s c l o s e l y p a r a l l e l l i n g those  for  January.  The further  increased d e n s i t y of  source waters near s i l l  c o n t i n u e d the exchange of  January.  Again  values at a l l depths  mouth)  increased during February,  0.5  changes observed a t depth  the oxygen  (except  ml/1 a t d e p t h t o g r e a t e r t h a n  34  I n d i a n Arm w a t e r s w h i c h had begun  r e f e r r i n g f i r s t to  oxygen  d e p t h a t Van  section,  it  i s noted  in that  i n a shallow s u r f a c e l a y e r near  with  changes r a n g i n g from l e s s  4 . 0 ml/1 n e a r t h e  head.  i n d i c a t e a l e s s e r moderation of  The  the  than  small  intruding  w a t e r s due t o m i x i n g ,  as w a t e r s  much more o x y g e n  surface outflowing waters  January. reflect  Large oxygen the f u r t h e r  toward the Ind 2 , case  rich  head.  crossing  the s i l l  t h a n was t h e c a s e i n  increases recorded i n waters near  displacement of waters  Waters  from d e p t h ,  s h a l l o w e r than about  with  the  head  upwards  25 m d e p t h ,  and  north  of  a g a i n a p p e a r t o h a v e b e e n p u s h e d up t h e n o r t h s l o p e , a s was  in January.  pre-January  These  i n t u r n must have d i s p l a c e d t h a t  deep w a t e r w h i c h r e s i d e d h e r e i n J a n u a r y ,  had a l m o s t e n t i r e l y b e e n f l u s h e d o u t o f Low o x y g e n  manifestation of  From t h e t e m p e r a t u r e ,  the presence of  c o n t i n u e d and a l m o s t c o m p l e t e e x c h a n g e  substantial  drop  (certainly  m u s t r a t h e r be i n d i c a t i o n o f  it  isohaline  isotherm)  old,  layer.  February  low oxygen  water.  further  is available.  c a n n o t be a s c r i b e d t o  a volume exchange of  I n d i a n Arm d u r i n g F e b r u a r y . is clear  that  at  t h e Arm p r e v i o u s l y .  Again,  the  i s o p y c n a l over  at  The  cooling  l e a s t 80% o f  L i k e w i s e from the  l e a s t those waters  had i n t r u d e d s i n c e J a n u a r y ,  a n d t h e a^ = 2 1 . 5  head i n  now  i n t e m p e r a t u r e o f w a t e r s d e e p e r t h a n a b o u t 20 m  beneath the 7 . 5 °  capacity of  the  a n d w h i c h by  s a l i n i t y and d e n s i t y s e c t i o n s ,  evidence of  the  p o r t i o n of  t h e Arm i n t h e s u r f a c e  c o n c e n t r a t i o n s near the s u r f a c e at the  marked the f i n a l  section  w e r e now m i x e d  below the  the  salinity  27.4°/oo  a s no 2 7 . 4 ° / o o w a t e r was f o u n d  c o n t i n u i t y of the s i l l  in  the 2 7 . 5 ° / o o i s o h a l i n e  s u g g e s t s an o n g o i n g  a t the t i m e t h e s e o b s e r v a t i o n s were r e c o r d e d .  but  exchange  94 March 2 6 ,  1975  Burrard Inlet I n d i a n Arm  (no s e c t i o n s  (Figures  The a l m o s t u n i f o r m 7 ° C w a t e r Inlet  i n M a r c h m a r k t h e end o f  commencement o f previous water  (d))  temperatures observed i n  the w i n t e r  cooling trend. small  50 m d e p t h a t  February c r u i s e ,  t h i s same s t a t i o n . to those of  d e c r e a s e d by 0 . 7 8  at depth.  there  of  S i m i l a r shapes of  the noted d e n s i t y decreases at depth  cruise.  February  depth,  but  the contours  comparable  had in  February  c o n d i t i o n s , w i t h the  exception  i n s i d e Second Narrows.  Only  t h e oxygen  d i s t r i b u t i o n was t h e r e a n y m a j o r c h a n g e , w i t h i n c r e a s e s  throughout  the  i n l e t of  0.5 ml/1.  I n c r e a s e s e x c e e d i n g 1 ml/1  most p r o b a b l y r e f l e c t i n c r e a s e d oxygen from  Indian  The earlier  exchanges at  the  i n the outflowing  I n d i a n Arm s e c t i o n s f o r  two l e v e l s a c r o s s t h e s i l l .  exchanges are p o s t u l a t e d .  4 . 8 ml/1  content  a t Van  34  waters  A s e v i d e n c e d by w a t e r  l a t e March suggests The  following  beneath the  7.1°  t h e 2 7 . 6 ° / o o i s o h a l i n e , and p o s s i b l y t h e d e e p e r p a r t i s o p l e t h of  oxygen,  there  had b e e n f u r t h e r  i n t r u d i n g v o l u m e was r a t h e r  s m a l l e r t h a n d u r i n g F e b r u a r y as  the  displacement of  towards  less.  of  the  the February c r u i s e .  h e a d was a p p a r e n t l y  an o x y g e n minimum l a y e r e x t e n d i n g  the  intrusion  bottom,  deep w a t e r s  after  deep w a t e r  of  down t h e s o u t h s l o p e t o t h e  development  in  Arm.  s t r u c t u r e of  isotherm,  19.  approximately  v a l u e s were  at s i l l  and M a r c h r e f l e c t t h e b a s i c s i m i l a r i t y o f  the  had b e e n a 0 . 9 5 ° / o o d e c r e a s e  Similarly,  F e b r u a r y 21  Along with  l a t e March  d e p t h a t Van 34 s a l i n i t y had i n c r e a s e d by the  Burrard  increases over  s a l i n i t y a l s o c l o s e l y matched t h a t  (to w i t h i n 0.04)  of  through  t e m p e r a t u r e s w e r e r e c o r d e d on t h i s  0.07°/oo since at  5.27(a)  an i n c r e a s e i n a i r t e m p e r a t u r e s ,  The d i s t r i b u t i o n o f While at s i l l  presented)  southwards from  The  The the  95 h e a d b e t w e e n 30 m and 100 m d e p t h was n o t e d . e n t e r e d t h e Arm e a r l i e r i n F e b r u a r y , displaced  upwards t o about t h e s e d e p t h s  the  however,  February 21.  This  o f deep w a t e r  sill  Van 34 m u s t h a v e r e a c h e d a l o w e r d e n s i t y s u c h t h a t  it  c o u l d no  t h e deep w a t e r  continued to  however,  i n I n d i a n Arm.  intrude at  m a j o r deep w a t e r  Most p r o b a b l y ,  a t these s h a l l o w e r depths penetrated f u r t h e r top of at  volumes  the l a t e March c r u i s e ,  defined.  deep w a t e r  April  29,  1975  Burrard  spring April  preventing at  Inlet  late April  conditions.  (Figures  (Figures  least for  5.28(a)  5.29(a)  a time,  any  inflow.  the further  through  through  (d))  (d))  s e c t i o n s i l l u s t r a t e a t r a n s i t i o n from w i n t e r Warming a t a l l  locations in Burrard  r a i s e d t e m p e r a t u r e s by 0 . 5 t o  b e t w e e n 7 . 3 ° and 9 . 7 ° C . develop near the s u r f a c e .  Stronger  Inlet  to  through  2 . 0 ° C , w i t h v a l u e s now r a n g i n g  temperature  Salinities  and  this shallow intrusion represents  exchange.  I n d i a n Arm The  the  Prior to,  W a t e r s d e e p e r t h a n a b o u t 50 m had d e n s i t i e s g r e a t e r t h a n d i d thereby  depth;  northward,  a s i m p l e e s t u a r i n e e x c h a n g e w i t h s u r f a c e o u t f l o w and m i d - d e p t h  inflowing waters,  of  i n t r u d i n g waters  and f u r t h e r  t h e o x y g e n minimum l a y e r became more w e l l  the time of  As  at  longer  l e v e l s n o t much g r e a t e r t h a n s i l l  e x c h a n g e had s t o p p e d .  at  Later,  depth  small  21.  after  I n d i a n Arm. at  water  a s d e n s i t i e s a t Van 34 d r o p p e d ,  in  the water  displace  moved  a t a t i m e when t h e d e n s i t y o f d e e p w a t e r  g r e a t e r than t h a t  had  water  some t i m e f o l l o w i n g F e b r u a r y  changes i n t h e deep w a t e r o c c u r r e d s h o r t l y  l a t e February c r u i s e ,  Van 34 was s t i l l  before  o l d e r water which probably  s o u t h w a r d b u t was m o d i f i e d by m i x i n g a t i s probable that  i n t h i s tongue  p o s s i b l y a s d e e p w a t e r w h i c h was  now f o r m e d an i d e n t i f i a b l e : l a y e r o f  It  The w a t e r  at  less  gradients than  had begun  15 m d e p t h  in  to the  96 approaches  had d e c r e a s e d by up t o 4 ° / o o ,  20 m d e p t h  had n o t  harbour,  Arm s i l l  changes  depth  0.39°/oo,  being near 2 ° / o o .  corresponding density  were s i m i l a r to  those recorded  s u r f a c e being a s c r i b e d to  The A p r i l further  deep w a t e r  exchange  the October -  explained  i n terms  of  Second Narrows Van 34 w i t h  As the  i n e a r l i e r months,  oxygen  r i c h water Indian  s a l i n e waters  distribution.  (oxygen c o n c e n t r a t i o n  Arm.  Consequently,  i n March must  have  75 m i n M a r c h t o  satisfy  volume  to  inflow,  indicate  to  Its  being f o r c e d upward,  for the  values the  that the  but  exchange  on A p r i l  must and  at  29.  changes were o b s e r v e d than about  90 m,  had i n t r u d e d  by t h i s  that  the  t h e volume  of  be  across  dense waters  core rose from  oxygen  to  vicinity  time  in  oxygen into  developed  approximately oxygen  i n the d i s t r i b u t i o n .  i t m u s t be i n f e r r e d compensate  the  5 . 2 ml/1)  however,  up  A s was  minimum l a y e r w h i c h had  changes  Indian  changes cannot  tidal  of  there  greater  exceeding  n e a r 50 m i n A p r i l ,  had i n c r e a s e d t o  In a d d i t i o n  depths  the  c o n d i t i o n s a t Van 3 4 ,  observed  been pushed u p w a r d .  continuity,  5.29)  the A p r i l  replacement  the oxygen  c o n s u m p t i o n was c o n t r i b u t i n g to  all  approaches,  production.  the most pronounced At  the  Oxygen  place during A p r i l .  period of the  than  below  i n c r e a s e s near  a p e r i o d of dense i n f l o w from this  In  i n the  0.40.  small  (Figures  late April  must a c c o u n t f o r less  Arm  November i n t r u s i o n ,  Following  the  decreases of  had t a k e n  ambient  a g a i n be t h e r e s u l t o f Van 2 4 .  30°/oo water  s a l i n i t y decreases of  in March, with  Indian  than  Waters deeper  increased biological  sections for  case with  west of  recorded  a t Van 34 had e x p e r i e n c e d  with  the  changed a p p r e c i a b l y from March l e v e l s .  l e s s e r s a l i n i t y d e c r e a s e s were  w i t h maximum  however,  surface inflow  minimum l a y e r  Nevertheless outflow at  depth.  had  become  97 more e l o n g a t e d t h a n the south s l o p e . approximately  evidence of  south of  Ind  1,  almost  O x y g e n c o n c e n t r a t i o n s i n t h e c o r e had d r o p p e d  1 ml/1  associated with  i n M a r c h , now e x t e n d i n g  to  l e v e l s below 3 . 6 m l / 1 ,  evidence of  i n c r e a s e d p r o d u c t i v i t y near the  c o n s u m p t i o n was n o t e d a t  the deepest point  v a l u e s dropped m a r g i n a l l y below 5 . 2 m l / 1 . c o n t i n u e d above s i l l  depth,  surface.  c o n t r i b u t i n g to  Estuarine  to  by  consumption Similar  i n the Arm,  exchange  h i g h oxygen  as  probably  values  in  the  u p p e r 40 m.  The  s a l i n i t y and d e n s i t y s e c t i o n s y i e l d f u r t h e r  intrusion March to Ind  at depth.  The  65 m i n A p r i l ,  2 7 . 6 ° / o o i s o h a l i n e r o s e f r o m n e a r 175 with  the actual  s a l i n i t y increase at  2 being 0 . 1 4 ° / o o , from 2 7 . 6 0 ° / o o to 2 7 . 7 4 ° / o o .  such s a l i n i t i e s  evidence of  were r e c o r d e d w i t h i n  5 m of  dense  m in  200 m a t  On t h i s same  cruise,  t h e s u r f a c e a t Van 2 4 ,  w e r e n o t o b s e r v e d a t a n y d e p t h a t Van 34 n o r a t  Ind  0,  t h a t d e e p w a t e r e x c h a n g e had h a l t e d p r i o r t o A p r i l 2 9 ,  but  illustrating and t h a t  the  d e n s e w a t e r s w h i c h m u s t h a v e r e s i d e d a t Van 34 d u r i n g t h e e x c h a n g e subsequently corresponding  As waters April  been r e p l a c e d . to  Increases in  i n c r e a s e s i n s a l i n i t y , were near  t h e deep exchange w h i c h t o o k  place in April  in  Indian  Arm,  0.1.  involved  warmer  t h a n t h o s e r e s i d e n t i n t h e Arm d u r i n g M a r c h , t h e s t r u c t u r e o f temperature  maximum l a y e r  section is complicated.  had begun t o d e v e l o p ,  n e a r 50 m d e p t h ,  the A p r i l  at depth are f u r t h e r  i n the month,  as l a t e A p r i l  Whereas i n M a r c h , a  extending  southwards  s e c t i o n i d e n t i f i e d a minor  minimum l a y e r a t a b o u t 75 m d e p t h . 7.3°C  at depth  had  temperature  from the  head  temperature  Water t e m p e r a t u r e s between 7 . 2  indication that  the  the exchange took  and  place early  t e m p e r a t u r e s e v e n a t Van 24 w e r e up t o  1.5°C  98 higher than t h i s v a l u e . 7.6°C  Nearer  isotherm i s probable evidence of  penetrating to approximately  This A p r i l exchanges of  stations  Ind  no f u r t h e r  section i n the  (later  1.5  in t h i s survey.  i n t e r v e n i n g months  deep w a t e r e x c h a n g e t o o k well  Observations  place,  at m a i n - l i n e  however,  and t h a t  represents the return  to  again  the  indicate August  summer c o n d i t i o n s  Arm.  June 13, The  1975  Burrard  Inlet  commencement o f  (Figures  b u t c o n d i t i o n e d by t h e  already  noted f o r  1975.  salinities however,  Temperatures  Burrard  to those recorded runoff  outflow  Salinities  i n the range  in  1975,  the June d i s t r i b u t i o n s ,  ranged from approximately  and S e c o n d N a r r o w s ,  a t Van 34 m a s k i n g t h e  the  previously.  C o n t i n u e d m i x i n g e f f e c t s were noted  s e c t i o n a c r o s s both F i r s t  volumes  later  9° to  w i t h the s t r o n g e s t g r a d i e n t s b e i n g observed i n the upper 5 m of column.  in  near the s u r f a c e i n  l o w e r r u n o f f peak i n  forms of  those observed  i n J u n e 1975  in  t h a n t h o s e r e c o r d e d two w e e k s  The g e n e r a l  to  observations  temperatures  S i m i l a r l y , due t o t h e  were s i m i l a r  (d))  i n c r e a s e d h e a t i n g and l e s s e r  Mid-June  were h i g h e r .  through  properties similar  a p p r o a c h e s w e r e h i g h e r i n 1975 the previous y e a r .  5.30(a)  t h i s second year of  I n l e t y i e l d s d i s t r i b u t i o n s of 1974,  the  winter  No s e c o n d a r y s a m p l i n g was  l a t e August.  and 2 i n t h e  presented)  in  inflow  c r u i s e m a r k s an end t o t h e o b s e r v a t i o n o f m a j o r  deep w a t e r  1,  continued estuarine  1.5  50 m d e p t h .  c o n d u c t e d i n I n d i a n Arm u n t i l  that  t h e s u r f a c e , the d i p n e a r Ind  i n the with  16°C, the  water  temperature I n d i a n Arm s u r f a c e  impact i n the near s u r f a c e  waters.  1 6 ° / o o t o n e a r 3 0 ° / o o were r e c o r d e d , w i t h  again  99 the  i n d i c a t i o n of  the  27  through  considerable mixing  through  2 9 ° / o o i s o h a l i n e s and c o r r e s p o n d i n g  s t a n d s a s an a n o m a l y ,  as a l m o s t s i m u l t a n e o u s  and a t  shown)  14-5  at depths stations of  (data  not  s h a l l o w e r than Van 1 1 ,  14 and 17  oxygen  layer, greater (not  productivity  and w i t h than  shown)  to depths  August  18,  Burrard  Burrard  1975  Inlet  i n August  and  As  mixing Narrows  1974,  is s t i l l  Salinities  above  6 . 5 ml/1  i n the  high surface  d a t a f r o m Van 3 4 ,  Ind  0,  having  Indian  5.32(a)  peaked  Arm.  1 and 2  through  gradients  i n August  1975  Narrows,  were  through  in July,  (d))  and w i t h  runoff  h i g h J u n e and J u l y  temperatures  observed  of  although  17°C  in July, i n the  consistent with  data  values,  however,  upper  earlier only  intense mixing  across  inlet generally  contours  exceeded  near  in  recorded  show e v i d e n c e o f  i n d i c a t e d by t h e d i v e r g i n g  June  (d))  i l l u s t r a t e l a t e summer c o n d i t i o n s Surface  at  Arm.  5.31(a)  s u b s t a n t i a l l y from  the  distribution.  lesser values  (Figures  approaches)  throughout  at  the  (Figures  and s t r o n g  across F i r s t  observed  14-2  a mis-sequencing  summer c o n d i t i o n s w i t h  w e r e down by 2 . 5 ° C f r o m t h o s e r e c o r d e d  15 m i n t h e  in July  Arm  Indian  the  14  27°/oo  salinity profiles  indication that  Van  a t Van  exceeding  in  accounting for  40 m i n  sections again  high temperatures (upper  Inlet  temperatures  having dropped  early  dip  e s t u a r i n e e x c h a n g e was r e s t r i c t e d d u r i n g  s h a l l o w e r than about  With a i r  the August  of  Density  indicate that  of  could account f o r  consumption  30 m d e p t h .  1975  no r e a d y  keeping values  detrital  Indian  volumes  gives  section is typical  biological  Inspection  The  isopycnals at  observations  recorded s a l i n i t i e s  10 m.  s a l i n i t y sample b o t t l e s  The  the Narrows.  10 m observations.  minor Second  10 m d e p t h .  2 0 ° / o o , and i n  fact  100 e x c e e d e d 3 0 ° / o o b e l o w 40 m d e p t h that As  i n the  previous year,  i n the temperature  Second Narrows Narrows. the  Low  i n the approaches.  30°/oo water  s e c t i o n , strong mixing  the  noteworthy  in late  September.  indicated across  i n August  First  account  for  s u r f a c e a t Van 34 a s o u t f l o w  Oxygen c o n c e n t r a t i o n s  high while further  is  i s indicated at  p r e c i p i t a t i o n and r u n o f f v a l u e s  Arm was w e a k .  remained  appeared is  w h i l e a n o m a l o u s l y weak m i x i n g  h i g h : s a l i n i t i e s recorded near  Indian  first  It  at depths  less  than  from  10 m  consumption d e c r e a s e s from J u l y were noted  at  depth.  By A u g u s t , a uniform greater 1974.  with  deep w a t e r  horizontal  than about Due t o  differences  d i s t r i b u t i o n of  50 m d e p t h ,  the extent  in temperature  intrusion  consistent with  of winter  magnitudes  Indian  Arm h a v i n g  a l l p r o p e r t i e s was n o t e d  exchange  and p r e c i p i t a t i o n r e g i m e s ,  in property  into  observations  and t o  however,  annual  ceased,  at  in  August  differences  significant  were r e c o r d e d from the  previous  summer.  Temperatures were 0 . 5 ° C  lower than  m i x i n g and t h e raised  i n t h e deep b a s i n ,  penetration  temperatures  nearly  temperatures  were  summer.  observed  is  The  1974  up t o  values.  Between  of  summer h e a t i n g  to  1974  2°C higher  structure  continued evidence of  though  levels.  about  At  11.5°  inflow  values,  60 and 100 m d e p t h ,  effects,  than those  i n the  estuarine  s i m i l a r to A p r i l  however,  the s u r f a c e , recorded  1975  i n the  through  13.0°  across the  sill.  had  previous  isotherms  101 By A u g u s t , April  maxima,  26°/oo  but were about  as 2 6 ° / o o w a t e r  a t Van 3 4 . previous do n o t ,  Near the  0.3  depth  to  0 . 4 ° / o o above  was p r e s e n t  surface,  had d e c r e a s e d m a r g i n a l l y  higher  1974  however,  reflect The  values.  lower depth  l i m i t to  only  than  deeper  s a l i n i t y values  summer a r e a g a i n c o n s i s t e n t w i t h w e a k e n e d  t h i s month.  1974  at  i s o h a l i n e marks an a p p r o x i m a t e  exchange,  in  s a l i n i t y values  the anomalously  the w i n t e r  estuarine August  than observed  1975  runoff:  high p r e c i p i t a t i o n  exchanges  The  40 m i n  higher d e n s i t i e s recorded i n August  are a consequence of  from  the  they  recorded  1975  than  and l o w e r t h a n  in  average  runoff.  Because of oxygen  section differs  however,  v  the major w i n t e r  the  former  (Figure  5.29(d)).  centred  at  i n t r u s i o n s through  s i g n i f i c a n t l y from  55 m d e p t h  the confined  in April  minimum a t a b o u t  90 m d e p t h  r a t e s were equal  at  However,  near the middle of  a l l depths,  oxygen  consumption  c o n s i d e r e d to rates  due t o  this  of  through  varying  rates  vary  be e v i d e n c e o f  consumption.  Nearer  the  surface,  oxygen  values  greater  depths  concentrations  with depth.  The  oxygen  due m a i n l y  to  remained g e n e r a l l y  values  inlet.  section  layer however, If  i n t h e months of  detrital  shift  is  eddy  continued  a  consumption  high p r o d u c t i v i t y 5.0  since  material,  transfer  and s u r f a c e  I i  and  replenishment  by up t o  ml/1.  of  instead  oxygen  had d r o p p e d  i n excess of  the A p r i l  i n d i c a t e a movement  an i m b a l a n c e b e t w e e n of  to  minimum  the  August  section;  There was,  s h i f t would  Below the depth  e s t u a r i n e exchange,  oxygen  the  1974  reference  had d i s a p p e a r e d .  t h e w a t e r mass i n t h e minimum t o April.  the August  c a n be i n t e r p r e t e d w i t h By A u g u s t ,  1975,  1.4  ml/1.  exchanges,  102 October 9, To  1975  patterns  temperatures in  Inlet  conclude the survey,  are presented. with  Burrard  1974.  The  (Figures Burrard  general features  i n the range  The  9° to  uniformity.  with  the  Narrows.  Low s a l i n i t i e s  temperatures  near the  and Second Narrows.  r a n g i n g from l e s s  near s u r f a c e  October  water  those  recorded  i s evidence of  the  than  (see F i g u r e  e f f e c t s of Finally,  3 ml/1  to  season.  extremely  4.1(a)).  strong t i d a l the oxygen  at depth  First  the  mixing  section,  to greater  i l l u s t r a t e s a t i m e o f maximum c o n s u m p t i o n  the high p r o d u c t i v i t y  trend  2 3 ° / o o and 3 0 . 4 ° / o o were  surface are a t t r i b u t e d t h i s month  1975  compatible  3 0 ° / o o i s o h a l i n e now r e a c h i n g 20 m d e p t h a t  As u s u a l , a l l s e c t i o n s i l l u s t r a t e t h e  6 ml/I  here i d e n t i f i e d are  S a l i n i t i e s between  high p r e c i p i t a t i o n recorded during  both F i r s t  (d))  s e c t i o n s from October  1 2 ° C were comparable t o  d i m i n i s h i n g range of  recorded,  with values  Inlet  through  and m e c h a n i s m s p r e v i o u s l y d i s c u s s e d .  toward w i n t e r  through  5.33(a)  than following  103 CHAPTER 6  CURRENT METER MEASUREMENTS  6.1  Time-Series Current 6.1.1  Location,  I n an a t t e m p t  Ind  Record  T i m i n g and Data  Recovery  t o measure n e a r - b o t t o m c u r r e n t s a t t h e mouth  I n d i a n A r m , an A a n d e r a a conductivity  Meter  and depth  r e c o r d i n g c u r r e n t meter w i t h attached  temperature,  s e n s o r s was d e p l o y e d i n t h e v i c i n i t y o f  0 on t h e c r u i s e o f December 5 , 1 9 7 4 .  mooring i s i l l u s t r a t e d i n Figure  1.1(b).  The a c t u a l  of  station  l o c a t i o n of the  Moored i n a p p r o x i m a t e l y  of water,  t h e i n s t r u m e n t was s u s p e n d e d a b o u t 3 m f r o m t h e b o t t o m ,  a buoyant  s u b s u r f a c e pontoon  clump b e l o w . conductivity  above,  a n d p r e s s u r e a t 15 m i n u t e  January  2 2 , 1975.  as w e l l  as the i n i t i a l  1975.  Deployment,  i n t e r v a l s through  temperature,  the period  I t was s e r v i c e d o n c e , on  s e r v i c i n g a n d recovery  of the instrument,  d a t a tape t r a n s l a t i o n were c o n d u c t e d under t h e  direction  o f M r . W . S . H u g g e t t a n d M r . F.  Currents  D i v i s i o n , Canadian Hydrographic  H e r m i s t o n o f t h e T i d e s and Service, Sidney,  inspection of the r e s u l t i n g record revealed that throughout  between  a n d an a c o u s t i c r e l e a s e a n d c o n c r e t e  The m e t e r r e c o r d e d c u r r e n t s p e e d a n d d i r e c t i o n ,  December 5 , 1974 t o M a r c h 7 ,  40 m  B.C.  the instrument  Detailed recorded  e f f e c t i v e l y the e n t i r e i n t e r v a l , with the only s i g n i f i c a n t  d a t a g a p i n t e r p r e t e d t o be d u r i n g a b o u t T h e r e a r e no o b v i o u s f e a t u r e s to suggest sensor f a i l u r e .  12 h o u r s . o n F e b r u a r y  19,  i n the data records of current or pressure  Constant  temperatures  during intervals  up t o a b o u t 3 0 h o u r s  i n the temperature  suspicion  c h a n g e s may a t t i m e s h a v e p a s s e d u n r e c o r d e d .  overall seasonal  that  trend  small  1975.  i n the temperature  r e c o r d , however,  of  introduce a The  r e c o r d does appear c o n s i s t e n t w i t h  c y c l e s d e s c r i b e d from b o t t l e  samples.  Similarly conductivities intervals  of  in the s a l i n i t y record and t e m p e r a t u r e s ) ,  6 to  giving this  appearance  as t h a t  of  of  constant  presented  to  suggests of  the  the  any  however,  and  (c).  Figure  January 4,  1975,  1975  hour.  6.2(a)  each hourly "stick"  It  one  1975  to  appears  temperature  set of  four  representation,  that  these  intervals  this  were  Figure  kind during trend  in  6.1  is  7 days  in  salinity  associated with small  intervals  these  periods  changes r a t h e r  than  in  Currents currents  two  current  6.2(b) 1975,  upper  1974  (b) to  and 6 . 2 ( c ) w h i c h s p a n  and F e b r u a r y 5 ,  The  1975  hourly  of  vector  four  traces  s a m p l e s c a l c u l a t e d by c o m p o n e n t s .  In  the d i r e c t i o n of  true  the vector  present  i s the  lower are  samples  averages  the  to  w h i l e the  component  a frequency  presents  period  traces in these figures  vectors. at  the  6.2(a),  5,  speeds r e s p e c t i v e l y ,  samples,  however,  in Figures  t h e p e r i o d December  by F i g u r e s  The  recorded over  i s presented  component  individual  "stick plot"  of  February 4,  of  month's  conductivity.  1975  i s followed  occasional  coincident with  the o v e r a l l  which spans  respectively.  from the The  of  to March 7,  is a "stick plot"  plotted  of  near-bottom  N o r t h - S o u t h and E a s t - W e s t trace  the  malfunction  Time-Series  periods January 5 , March 7,  record.  s a l i n i t y i s i n the r e s o l u t i o n of  1974  about  over  recorded  t i m e - s e r i e s t h e same " c l i p p e d "  i n c i d e n t s of  appearance  t i m e - s e r i e s of 5,  the  s a l i n i t y were g e n e r a l l y  instrument  6.1.2  December  of  temperature  the a b s o l u t e d e t e r m i n a t i o n  The  part  i l l u s t r a t e marked  that  salinities  and w e r e c o n s i s t e n t l y more f r e q u e n t .  Again,  constant  latter  temperature,  longer  February.  of  constant  generally  constant  20 h o u r s w e r e r e c o r d e d a f t e r  operation,  intervals  ( c a l c u l a t e d from the  per  from  this direction  105 toward which the  c u r r e n t f l o w e d , w h i l e the  r e p r e s e n t a t i o n of time s c a l e f o r  c u r r e n t speed  length of  (see o r d i n a t e f o r  a l l three traces i s presented at  the vector  scale).  The  the bottom of  c r u i s e n u m b e r s i n d i c a t e t h e d a t e s when w a t e r p r o p e r t y  is a common  the  page;  s a m p l i n g was  accomplished.  An  immediate i n t e r p r e t a t i o n f r o m b o t h t h e component t r a c e s  from the s t i c k  plot  i s that  t h e f l o w was r e s t r i c t e d t o at  approximately  occasionally, these,  two r a t h e r  the e n t i r e observation  currents flowed of  directions.  hourly average  From t h e C a n a d i a n H y d r o g r a p h i c  t h e mouth o f  I n d i a n Arm i s o r i e n t e d a t 3 4 0 ° -  ( I n d i a n Arm)  it  c u r r e n t meter r e c o r d f i r s t confirms t h a t  i s observed that  p e r s i s t i n g a t most f o r  (infrequently),  a p p e a r i n g t o be i n t h e r a n g e o f  The f e a t u r e exchange of (outflow),  of  principal  w i t h mean s p e e d s  10 -  is  the  basically  by t h e  three  approximately  of  winter  i s the v a r i a t i o n i n net Two  d o m i n a t e t h e r e c o r d , s e p a r a t e d by t r a n s i t i o n p e r i o d s . example,  channel  20 c m / s .  deduced from the c u r r e n t meter r e c o r d .  for  two t o  at  (over 2 to 3 days)  i n t e r e s t i n the context  I n d i a n Arm d e e p w a t e r s  (characterized,  Thus,  flow  From t h e s e p l o t s , maximum c u r r e n t m a g n i t u d e s o f  35 cm/s a r e n o t e d  these  the channel  160° True.  near-bottom  from  Service  long-channel d i r e c t i o n s , with s i g n i f i c a n t cross  flow being a t r a n s i e n t f e a t u r e , hours.  While  c u r r e n t s were w i t h i n ± 1 0 ° of  c h a r t 3435  to the  160° True.  centred  in significantly different directions  navigational  restricted  period,  narrow d i r e c t i o n a l bands,  3 4 0 ° T r u e and a t a p p r o x i m a t e l y  the majority  principal  throughout  and  interval  inflow  basic flow  regimes  I n some i n s t a n c e s ,  December 5 - 7 ,  Figure  6.2(a))  106 the. s e m i d i u r n a l down t h e inflow  tidal  channel  (i.e.  (outflow)  the m a j o r i t y  o s c i l l a t i o n appears  over  toward a tidal  however,  by t h e  interval  January 2 -  22,  regime  is evident,  is  for  two r e g i m e s  inflow  (outflow)  form of  the  6.2(a)  Figure the  Time-Series  6.3  from  The  interval  (in  conjunction with  up t o  0.2°  -  tidal  the f u l l  evident  fluctuation strong  i n t h e component  inflow,  of  at  outflow  depth is  dependent  these  upon  discussion of an  the the  averaged  over  data,  5,  of  1974  While  four  through  less  basic features These  changes  per  exhibits  tidal  Figure  frequency 6.2  1975 all  the  on a  range  i t m u s t be a s s u m e d t h a t a few hours  have  Fluctuations  6 hours  i n the  of  hour.  January 4,  record. than  records  points  6.1)  the e n t i r e  periods of  t r a c e s of  at  Figure  typical  semidiurnal  Salinity  and s a l i n i t y .  periods of  more  and  i l l u s t r a t e the  s e t of  time-scale features  the  inflow  inflowing  p e r i o d s between  comprehensive  the e a r l i e r presented  0 . 4 ° C appear f r e q u e n t l y .  motion,  a second  a mean  l a t e r presented with  December  o c c a s i o n s , however,  temperature  net  of Temperature  1 . 1 ° were r e c o r d e d o v e r  number o f  of  temperature  here p r e s e n t e d ,  short  component  transition  A more  h a s been i n c l u d e d t o  a g a i n been p l o t t e d  net  Through  record.  t i m e - s e r i e s records of  principal  The  characteristics is  6.1.3  net  example,  and 6 . 2 ( b ) ) ,  Substantial  degrees  outflow.  c u r r e n t meter  Little  for  o s c i l l a t i o n about  340°).  i l l u s t r a t e varying  o f down c h a n n e l  the  tidal  p e r i o d s o f many d a y s .  extent  of  characterized,  (Figures  c o n s i s t i n g of  approximately  (as  s u g g e s t e d by t h i s c a s e , a s no s o u t h w a r d  evident  and  c y c l e i s s u g g e s t e d by s u c h a c a s e .  the r e c o r d ,  (towards  f l o w up  3 4 0 ° and 1 6 0 ° r e s p e c t i v e l y ) .  of  current  as a l t e r n a t i n g  of much  i s coupled  w h i c h was  i s not r e a d i l y  of to  clearly  apparent  107 except the  in scattered  i n s t a n c e s , i n the  e a r l i e r mentioned  on December  15 -  intervals  do n o t  of  0 . 1 ° C would  than  thermistor)  it  in temperature is  later  averages  have  22 -  were not  recorded. to  many o f As  identify  temperatures,  23.  the  the b i a s  and n o t  of  the  these changes  Aanderaa's small  fluctuations  temperature t o make  into  of  exhibited  (since  the expected  introduced  by t h e s e o c c a s i o n a l i n t e r v a l s  are  sensor,  averaged  trends  Examples  While  been u n r e s o l v a b l e w i t h  l i k e l y that  only  record.  temperature  n e c e s s a r i l y imply a f a u l t y  appears  employed  comparisons of  constant  16 and a g a i n on December  observations less  of  temperature  record  absolute  long-term  poor r e s o l u t i o n  i s not  expected  t o be s i g n i f i c a n t .  In c o n t r a s t salinity loss. most  record,  shows l i t t l e  Typical  fluctuations  of  of  one t o two  in intervals 6.3).  few h o u r s ) salinity  for  of  about  up t o  hours. six  the e n t i r e  changes  t i m e as w e l l  data  loss  due t o  oscillation  that poor  about  any  part  of  i n d i c a t i o n of  the data  0 . 1 ° / o o were o b s e r v e d  hours were r e c o r d e d  record.  i n excess of  if  the e a r l y  Maximum f l u c t u a t i o n s  Such changes r e p r e s e n t  this  record.  temperature  (Figure 6.3)  l.l°/oo  tidal  the  trace  intervals  Figure  to  the extremes  up  to  ( s e e December  (over  A f t e r January 2,  of  over  intervals  1975,  It  is  t h e s a l i n i t y r e c o r d shows p o s s i b l e e v i d e n c e  i s more e v i d e n t  small  fluctuations.  i n the s a l i n i t y than  of  a  short-term  0 . 5 ° / o o were seldom r e c o r d e d .  r e s o l u t i o n of  9,  after of  A semidiurnal i n the  temperature  108  6.2  Averaged Time-Series Current Meter Record 6.2.1 Averaging  In order to illustrate the character of net inflow (outflow) at depth, a simple averaging was undertaken to eliminate the major tidal component from the time-series of current, temperature, and salinity.  As earlier noted, the most significant tidal constituent in the area of Burrard Inlet is the Principal Lunar  component, having a  period of 12.42 hours. To remove fluctuations at this frequency from the time-series records, running means over six M2-cycles, (74.5 hrs, approximately three lunar days) were calculated. Each successive 74.5 hour interval commenced 24 hours (approx. two M periods) into the.preceding 2  interval.  Averaged component and stick plots of the records (corres-  ponding to those of Figure 6.2) are presented as Figure 6.4.  Similarly,  averaged temperature and salinity traces (resulting from those partially illustrated in Figure 6.3) are presented as Figure 6.5.  6.2.2 Time-Series of Averaged Currents The principal feature of both the component and stick plots of Figure 6.4 is the persistent net inflow (directed to the north northwest) recorded through the entire observation period. This is consistent with earlier conclusions drawn from the analysis of property distributions. An estuarine circulation of surface outflow and subsurface inflow during December through February was earlier inferred from the vertical sections for Indian Arm (Section 5.3). It is noted from Figure 6.4 that on only four brief occasions between December 5, 1974 and March 1, 1975 did the net inflow reverse.  On these instances, mean outflowing currents  of  less  t h a n 3 cm/s p e r s i s t i n g f o r  represent a very  small  comparison to the  volume  transport  out of  only  two t o f o u r  t h e Arm  (at  15 -  30 d a y s .  4 -  N e a r t h e end o f  ( d u r i n g t h e f i r s t week o f M a r c h 1975)  days  depth)  i n f l o w v o l u m e t r a n s p o r t e d by c u r r e n t s o f  which p e r s i s t e d a t times f o r interval  i n t e r v a l s of  in  12 c m / s  the r e c o r d i n g  a more s i g n i f i c a n t  outflow  a t d e p t h had commenced a s mean c u r r e n t s p e e d s r e a c h e d n e a r l y 7 c m / s . S e p a r a t e d by t h e b r i e f  p e r i o d s of  i n f l o w a r e i d e n t i f i e d on F i g u r e  outflow,  6.4.  These  December 14 -  December 27  14  days  December 29 -  J a n u a r y 24  27  days  J a n u a r y 27  March 1  33 d a y s .  -  6 . 2 . 3 T i m e - S e r i e s of Averaged Visual traces,  Figure  few days in  6.5,  periods  6.4.  of  The  Temperature  the averaged temperature  and  Salinity  and s a l i n i t y  r e v e a l s s t r o n g c o r r e l a t i o n between changes over  e a r l y stages of  the l a t t e r  i n f l o w are seen to c o r r e s p o n d to  decreasing temperatures densities)  o u t f l o w s w e r e a c c o m p a n i e d by i.e.,  two o f  In a l i k e manner,  (therefore,  i n c r e a s i n g temperatures  decreasing d e n s i t i e s .  The  the three  the  a  illustrated  t i m e s when r a t h e r  and i n c r e a s i n g s a l i n i t i e s  were b e i n g r e c o r d e d .  salinities,  of  are:  i n t h e s e p r o p e r t i e s and changes i n c u r r e n t p a t t e r n  Figure  periods  i n s p e c t i o n of  three major  major  sharply increasing  l a t e stages of  net  and d e c r e a s i n g  c o r r e l a t i o n between  t e m p e r a t u r e a n d s a l i n i t y c h a n g e s and c u r r e n t s a s s o c i a t e d w i t h t h e  onset  of  this  the f i r s t  i n f l o w p e r i o d i s not as s t r o n g .  p e r i o d f r o m December as were the o t h e r was r e c o r d e d .  The  commencement o f  14 was a c c o m p a n i e d by t h e u s u a l d r o p  periods,  As a b r i e f  however,  in  temperature  no s i g n i f i c a n t i n c r e a s e i n s a l i n i t y  i n t e r v a l of  n e t o u t f l o w d e v e l o p e d on December  27,  water  temperatures  increase.  continued to f a l l ,  rather  A sharp decrease i n s a l i n i t y was,  than showing the however,  usual  recorded at  this  time.  6.3  R e l a t i o n of  Current Meter Record to Property  Distributions  The a b o v e d e s c r i b e d o b s e r v a t i o n s a p p e a r t o be f u l l y with in  changes i n the  section 5.3.  noted to 1975,  It  will  be r e c a l l e d  the temperature considerably  14 -  27  and s a l i n i t y d a t a o f  less  dense water  no d e e p e r t h a n t o a b o u t  therefore,  be c o n c l u d e d t h a t i n f l o w across the  distributions salinity  1975  Figure  at  later  sill.  from  of  inflow events.  60 m i n s i d e t h e  I n d i a n Arm  cruise.  No  in Indian  It  Arm  have  must,  sill.  commenced a b o u t  As no u n u s u a l  f i v e days p r i o r  changes i n  a t d e p t h w e r e r e c o r d e d on t h i s c r u i s e ,  it  i s probable that  t h i s period penetrated  the  and a s s i g n i f i c a n t about  i n f l o w i n g waters  to only mid-depth  Commencing on J a n u a r y 3 ,  to  property  i n f l o w i n g w a t e r d i d n o t commence u n t i l  t h e f i r s t few days o f  i n I n d i a n Arm.  i s seen  t h i s t i m e w e r e shown t o  6.5)  100 m)  6.4  6 . 5 t o have been  January 2 (see F i g u r e  than  3,  t h i s December e v e n t was e s s e n t i a l l y an  i n f l o w event  i n c r e a s e s i n the  of January  year.  i n the denser water a t depth  penetrated  the January 3 ,  that  than were the  December and i n f l o w i n g w a t e r s  The s e c o n d m a j o r  of  i n f l o w i d e n t i f i e d on F i g u r e  changes were observed  estuarine  t h a t m a j o r d e e p w a t e r e x c h a n g e was  have c o n t i n u e d i n t o A p r i l  The D e c e m b e r  during  distributions e a r l i e r discussed  h a v e commenced a t some t i m e f o l l o w i n g t h e c r u i s e  and t o  major  I n d i a n Arm p r o p e r t y  consistent  however,  in  (less t h e mean  salinity  of  providing in  the  i n f l o w i n g water  s u f f i c i e n t l y dense water  I n d i a n Arm.  6.4)  With minor  and i n s a l i n i t y  approximately  at  net  inflow  volume water. were  when t h e  this  had t r a n s p o r t e d  time,  net  23,  in following  passed through  section)  change,  previous  t h i s event  substantial Figure  6.4.  inflow  c u r r e n t meter  net outflow  noted  That a major  inflow  Indian  was  with  the  Indian  Arm  (section  i m p l i c a t i o n s of  the  5.3).  of  net  experienced.  of  the  outflow  led to  the r e c o r d  the  its  significant  the of  period sections  consistency i s again record.  with  respects to  dominance of  few days  and  sill.  inflow,  33 d a y s u n t i l  had o c c u r r e d d u r i n g  c u r r e n t meter  Arm  intensities  s i t e on t h e  i n t h e e n s u i n g week t h e n  Thus,  of  a maximum a n d s a l i n i t y  J a n u a r y 23 t o M a r c h 7 was i l l u s t r a t e d e a r l i e r f r o m p r o p e r t y through  As  period  and o u t f l o w  Increasing  i n the f i n a l  mean  0.4°/oo.  27 d a y  S i m i l a r i n most  March 1.  until  c e a s e d , the  transport  interval  continued for  (Figure  current  indigenous  c u r r e n t meter  commenced.  commenced a g a i n a b o u t the  the  the t h i r d major  associated density  the depth of  of  passed through  minima a t  this  depths  to d i s p l a c e a s i g n i f i c a n t  almost n e g l i g i b l e net  About January 27,  outflow  continued  inflow  however,  s u f f i c i e n t water  temperature  interval,  inflow  speed  s i t e had d e c r e a s e d by a b o u t  c r u i s e of January  s i m i l a r , such t h a t  density  at  strong  /oo,  the g r e a t e s t  i n mean c u r r e n t  B e t w e e n J a n u a r y 24 a n d J a n u a r y 27  During  to  0.7  16 a t w h i c h t i m e a d e c r e a s e i n mean  the c u r r e n t meter  (see e s t i m a t e s  to penetrate  this  By J a n u a r y 2 4 ,  c o n f i r m e d on t h e  i n c r e a s e d by a b o u t  fluctuations  (density)  January  s p e e d commenced. salinity  rapidly  observed  112 It Figure  is clear  6.5 that  f r o m t h e mean t e m p e r a t u r e  the d i f f e r e n t  associated with waters  of  March 1 ) ,  density.  (December  27  t h e o u t f l o w i n g w a t e r was o f  was w a t e r o f following)  the preceding ;(and  inflow periods.  for  -  29,  a n d J a n u a r y 24 -  c u r r e n t meter  (37  m depth) at  that  it  i s the d e n s i t y of  27)  the n a t u r e o f deep f l o w  periods,  the s a l i n i t y (and,  into  than  l ° / o o were r e c o r d e d a t  s i m u l t a n e o u s measurement a t concluded that times of  the  net outflow  surface outflow. of  this outflowing  6.4  less  Property (Figure 5.24)  (for  than the from  example  determined at  in a t )  of waters  l e a s t a few t e n t h s  Maximum s a l i n i t y e x c e s s e s o f  t i m e s , of  t h e 40 m b o t t l e  the c u r r e n t meter.  Thus,  i s a deeo m a n i f e s t a t i o n o f  of  the a  part  waters greater  sample over i t must  the  be  c u r r e n t meter  lighter  Indian  The m e c h a n i s m w h i c h d e t e r m i n e s t h e d e p t h o f l a y e r i s not evident  these in  higher than the s a l i n i t y of  dense water f l o w i n g p a s t the  from the p r e s e n t data  during  Arm penetration base.  Volumes  Method  d i s t r i b u t i o n data from the c r u i s e s and F e b r u a r y  the  ultimately  Even d u r i n g  the d e n s i t y )  Deduced V e r s u s M e a s u r e d I n f l o w 6.4.1  net outflow  Indian Arm.  therefore,  the c u r r e n t meter.  post  sample s a l i n i t i e s  a t Van 34 w h i c h  d e p t h r a n g e 3 0 m t o 40 m a t Van 34 was a t  surrounding  and  instances, of  with s a l i n i t i e s  source waters  (a f e w t e n t h s  net  t h e c o r r e s p o n d i n g t i m e s g i v e s no i n d i c a t i o n  controls  per thousand  bottle  are  i n s t a n c e s of  29, January 2 4 - 2 7 ,  t h e f i r s t two  Comparison of  27 -  In a l l  relatively lesser density  30 m a n d 40 m d e p t h a t Van 34 a t t i m e s o f December  of  f l o w regimes past the c u r r e n t meter  different  o u t f l o w a f t e r mid-December  and s a l i n i t y d a t a  19 and 2 1 ,  of  (Figure 5.26),  January  23  coupled with  the  113  averaged  c u r r e n t meter  the comparison of areas under the (the  run past  calculated. inflow,  component  the meter In  Figure  estimates  Computations  versus  deduced  An e l e m e n t  i n f l o w volumes. speed,  and w e s t  Simply,  between  component  a r e now u n d e r t a k e n  i n f l o w volumes  for  the  directions)  an a s s u m e d c r o s s - s e c t i o n a l estimates of  area  to allow  dates are  of  i n f l o w volume.  the  for  selected  These  i n f l o w volume deduced f r o m t h e  Preparatory required  assumed c r o s s - s e c t i o n a l purposes  of  property  comparisons  latter  through Thus,  inflowing  layer  entire  layer.  40 m.  Two  area of  both  two  inflow  intervals  Calculations  of which a uniform  current meter.  (but  different)  Maximum  this  point  depth a t  The  the  surface  4 for  10 m s u r f a c e l a y e r :  1.59  x 10  (b)  for  15 m s u r f a c e l a y e r :  1.06  x 10  2 m  4  2 m .  in  profile  the of  c u r r e n t meter inflow  l a y e r depths  are:  (a)  the  area of  cross-sectional  deep  be r e p r e s e n t a t i v e  l o c a t i o n of  cross-sectional  resultant  1450 m c h a n n e l w i d t h  assumed t o  areas of  of  the  circulation  current  meter  is For  and an i n f l o w i n g  c u r r e n t s measured by t h e n e a r - b o t t o m are at  comparisons  idealized estuarine  surface layer  assuming o u t f l o w i n g  respectively.  and  i n f l o w p a s t the  comparison,  an o u t f l o w i n g  c a l c u l a t i o n s of  undertaken,  Assumptions  i n m a k i n g s p e e d and v o l u m e  an i n i t i a l  assumed, w i t h  exists.  an o p p o r t u n i t y  6.4.  6.4.2  layer,  of  provide  averaged  i n the north  t h e s e are used t o g e n e r a t e  of measured  is  curves of  conjunction with  distributions.  the  (Figure 6 . 4 ) ,  d e d u c e d and m e a s u r e d  a r e compared w i t h  of  record  have  the is  been  10 m and 15 m  inflow for  the  114 In p r e p a r a t i o n vertical  f o r making e s t i m a t e s  s e c t i o n s , an i r r e g u l a r t h r e e  enclosing  Indian  w e r e made.  Arm,  and v o l u m e e s t i m a t e s f o r  each having a r e l a t i v e l y  by t h e  segment.  of  t h e segment  of  information  estimates  from  29,  1974  Inflow 6.4,  evident  Interval  a net  likely this  29,  1975.  this  period,  to mid-depth  r e c o r d e d on J a n u a r y 2 3 )  21  10 m l a y e r s ,  volume  the  this  December  conditions)  Thus,  21 d a y s ,  it  Indian on  it  December is  5 and  suggested the  commencing  assumption  i s that  on  any  water  29 and J a n u a r y 3 was  i n t r u s i o n commenced.  inflow  i s assumed i n t h e  period  i n t h e Arm was  i n f l o w between  December  net  1975  sampling i n  i n f l o w event which led to  between  days o f  over  at depth  a t most m i d - d e p t h .  Further j u s t i f i c a t i o n for  a p e r i o d of  the  to January 24,  property  properties  i t s e l f r e p l a c e d when t h e more d e n s e  basis,  of  on J a n u a r y 3 and a g a i n  (from e a r l y  of the  1974  i s noted  Water  i d e n t i f i e d by J a n u a r y 23 was a b o u t  which intruded  volume  sectioned into  i n f l o w at depth  As no c h a n g e i n w a t e r  probable duration  January 3.  of  Multiplication  e a c h s e g m e n t was c a l c u l a t e d .  December  to January 24,  J a n u a r y 3 was r e s t r i c t e d t o  overturn  cross-section  sections.  on t h e J a n u a r y 3 c r u i s e  the  segments,  i t s area c a l c u l a t e d .  was e a r l i e r c o n c l u d e d i n S e c t i o n 5 . 3 t h a t  that  element  A representative  hypothetically  Arm was c o n d u c t e d t w i c e d u r i n g January 23.  visualized  into eight  g a v e an e s t i m a t e  from  i s q u i c k l y p o s s i b l e t o make r e a s o n a b l e  longitudinal  From F i g u r e December  it  g r i d was  each g r i d  length  each such l a y e r w i t h i n  With t h i s  6.4.3  and  then  The Arm was f u r t h e r  and t h e v o l u m e  its  uniform width.  across each segment,  length  i n t r u s i o n volumes  dimensional  The Arm was d i v i d e d a l o n g  was p l o t t e d  of  (leading  to  the  On  changes  following calculations.  In oxygen  the d i s c u s s i o n ( S e c t i o n  s e c t i o n , Figure  5.24(d)  3 . 6 ml/1  i s o p l e t h of  intruded  and i n d i g e n o u s w a t e r s .  Volume  of  oxygen  intruded water  at depths  greater  I n summary  than  5.3)  of  t h e J a n u a r y 23 I n d i a n  i t was shown t h a t  the  m a r k s an a p p r o x i m a t e  north  boundary  Maintaining this of  Ind  0 to  3 . 2 ml/1  the f o l l o w i n g  t h e 3 . 2 ml/1  quantities  or  the  between  as an a s s u m p t i o n ,  have  isopleth,  x  10 m, was c a l c u l a t e d t o be 1 . 2 4  then,  Arm  9  the  and  3 m .  10  been deduced  or  measured: i n f l o w volume  -  c r o s s - s e c t i o n a l i n f l o w a r e a a s s u m i n g a 10 m deep s u r f a c e l a y e r  X  :  cross-sectional inflow deep s u r f a c e l a y e r  X  2  -  -  p e r i o d of  distributions)  a r e a a s s u m i n g a 15 m  the e a r l i e r described method,  traces of  Figure  6.4,  between  J a n u a r y 23 w e r e c o m p u t e d y i e l d i n g : p a s t the  x 109  m3  = 1.59  x 104  m2  = 1.06  x 104  m2  t = 21  inflow  Employing component  (from property  V = 1.24  -  (for  the  days  areas under  the  dates  of  the  components  the  J a n u a r y 3 and of water  run  meter)  Northwards  1.78  x 105 m  Westwards  7.24  x 10  4 m.  5 From t h e s e a r e s u l t a n t r u n o f Again 6.4.2,  employing  the  two  as:  x 10  m was c a l c u l a t e d .  c r o s s - s e c t i o n a l areas discussed i n  i n f l o w volumes ( e s t i m a t e d  calculated  1.92  from the  c u r r e n t meter  section  record)  were  116 V-^ = 3 . 0 5 x 10 V  2  The  9  = 2.04 x 109  m  3  for  10 m s u r f a c e  outflow  m3 f o r  15 m s u r f a c e  outflow.  c o m p a r a t i v e f i g u r e , deduced from water  recalled  to  be 1 . 2 4  6.4.4 The f i n a l extends  x 109  Inflow  27  Interval  c u r r e n t m e t e r r e c o r d , an i n t e r v a l  of  actually  1975.  For  inflow event, for  of  1975  record  the purpose  of  21  of  such c a l c u l a t i o n s .  27.  Thus,  c a n be a s s u m e d t h a t  r e c o r d e d on F e b r u a r y  distributions  the c r u i s e  e f f e c t i v e l y zero  24 and J a n u a r y  present c a l c u l a t i o n s , i t  distributions  to March 1,  over which changes i n p r o p e r t y  this final  between J a n u a r y  1975  c o n s i d e r a t i o n m u s t be r e s t r i c t e d t o a  p r o v i d e s an a p p r o p r i a t e o p p o r t u n i t y  evident  27,  to about March 1 ,  p e r i o d s p a n n e d by c r u i s e s , During  January  i d e n t i f i e d on t h e c u r r e n t m e t e r  volume c a l c u l a t i o n s , however,  were measured.  be  m3.  i n f l o w event  from January  p r o p e r t y measurements w i l l  27  From  the  net outflow  for  the  is  purposes  the changes i n  (from January  evolved over the p e r i o d January  February  property  23 c o n d i t i o n s )  to February  21;  a span  of  26 d a y s .  Earlier discussion  in Section 5.3  had t a k e n p l a c e b e t w e e n J a n u a r y that waters  at  a l l depths  23 and F e b r u a r y  beneath the 7 . 5 °  had i n t r u d e d s i n c e t h e l a t e J a n u a r y a boundary,  i l l u s t r a t e d that major  cruise.  is  noted that  a l t e r a t i o n of  cause a r e d u c t i o n of  only  1.85  was c o n c l u d e d  Accepting t h i s  a n d a s s u m i n g a 10 m t h i c k n e s s f o r  a minimum i n t r u d e d v o l u m e o f  It  isotherm (Figure  the outflowing 9  layer,  21.  x 10  exchange  5.26(a)) i s o t h e r m as surface  3 m  was c a l c u l a t e d .  surface layer thickness to  3% i n t h e e s t i m a t e d v o l u m e o f  15 m w o u l d intrusion.  (It  21  This  effect  i s considered i n s i g n i f i c a n t ,  e s t i m a t i o n of  c r o s s - s e c t i o n a l area at the  which the  change  reduction  in  in surface  layer  c u r r e n t meter  thickness leads to a  the  pertinent  parameters  as  for  one-third  February  follows: m3  a r e a a s s u m i n g a 10 m  Xj = 1.59 x 10  4  m2  X  4  m2  cross-sectional inflow deep s u r f a c e l a y e r  -  c r o s s - s e c t i o n a l i n f l o w a r e a a s s u m i n g a 15 m deep s u r f a c e l a y e r  -  p e r i o d of  (from property  2  x 10  = 1.06  t = 26 d a y s  inflow  areas under  Figure 6.4,  the  9  -  to  location  of  V = 1.85 x 10  i n f l o w volume  computed  case  distributions)  -  of  the  associated with  have been c a l c u l a t e d o r e s t i m a t e d  The  to  area).  In summary, intrusion  in contrast  the  between  component  the dates  of  traces  (the  J a n u a r y 27  run past the  meter)  and F e b r u a r y 21  were  be: x 105 m  Northwards  1.50  Westwards  5 . 8 2 x 10  m.  5 The  corresponding resultant  multiplied estimated  by t h e inflow  two e s t i m a t e s volumes  9 = 2 . 5 5 x 10 V2  m  The 1.85  x 10  1-70  comparative  x 10  9  m3.  of  x 10  m , w h i c h when  c r o s s - s e c t i o n a l inflow area y i e l d s  of:  3  9 =  run i s 1.61  for  10 m s u r f a c e  outflow  for  15 m s u r f a c e  outflow.  3 m  figure,  deduced from water  property  measurements  is  118  6.4.5 Table  6.1  Summary  (below)  and D i s c u s s i o n  h a s b e e n c o m p i l e d a s a summary  in  t h e p r e c e d i n g two s e c t i o n s .  of  i n f l o w volume  to total  Also  recorded  I n d i a n Arm volume  here  ( i n %) a r e c o m p a r i s o n s  f o r t h e two i n f l o w 9  Total  Indian  Arm  volume  i s approximately  TABLE  of the c a l c u l a t i o n s  events.  3 m .  2 . 3 x 10  6.1  SUMMARY OF VOLUME COMPARISONS Volume f r o m Property Distributions  CrossSectional A r e a (m2)  Inflow Interval  1.24  x 10  54  2.04  x 104  1.85  x 109  80  2.55 x  109  111  x  1.85  x 109  80  1.70 x 109  74  x  104  1.24  x  Jan  23/75  1.06  x 104  Jan  27--  1.59  Feb  21/75  1.06  this  is first  a factor  inflow events  and v a r i o u s  10  figures  of 2 . 5 , suggesting that  c o n s i d e r a t i o n c a n be g i v e n  the January  scales  order  89  agree  to  estimated  of magnitude.  t o t h e noted  for Given  differences,  c a s e , assuming a s u r f a c e o u t f l o w  l a y e r d e p t h o f 10 m  inflow period,  estimated  record i s 2.46 times  distributions.  Increasing  to 1.65.  differences.  a l l comparative  x  9  r e a s o n s f o r t h e s e c a n be s u g g e s t e d .  c u r r e n t meter  factor  that  109  are c e r t a i n l y of the proper  In t h e w o r s t during  104  t o be n o t e d  (at worst)  acceptance,  133  9  1.59  the  % of Total  3.05 x 109  3 -  within  % of Total 54  Jan  It  Volume from Currents (m§)  that  estimated  from  the s u r f a c e l a y e r depth  Two o b v i o u s  Firstly,  t h e i n f l o w volume  possibilities  i t i s unlikely that  exist  from t h e  property  t o 15 m r e d u c e s  to explain  the t o t a l  volume  this  these of  water  119 entering  t h e Arm d u r i n g t h e  s i m p l y from a p a i r probably water  of  subsequently  would  the volume estimates  leave  Some o f  entrained  i n the  t h e Arm by t h e  of volumes  it  i s to  a l e s s e r v e l o c i t y must the  interface  between  Additionally, lies  it  outside  is  First  water  the  have the  northwards  into  Indian Arm,  the dense f l o w would  have  Arm f r o m t h e v i c i n i t y o f through  the  current  to  to  It  the upper  turn  than  property  top  which low  through  of  flow  the dense i s hot  the  It  to the  entire  inflow  reversed. inflowing  inflow  those  at mid-channel.  agreement  the  dense  flows  Alternatively,  flow  shores adjacent  water  cross-  approached  In any e v e n t ,  waters  this  B a s i n and t h e n  as i t  layer,  representing  i s possible that  Burrard  left  the  l i k e l y that  a c t t o d e c r e a s e the volumes  distributions.  This  from  by a p r e s s u r e g r a d i e n t .  record, yielding better  is  c a l c u l a t i o n s were  some d e p t h ,  across the  Second Narrows.  be l e s s  v e l o c i t y would  c u r r e n t meter from the  as a t  source of  current  layer.  lead to  current  the d i r e c t i o n of  the  driven  the  near the  i n f l o w c r o s s - s e c t i o n along the  c o u l d be e x p e c t e d in  a l l volume of  to the west.  into  surface  t h e Arm  the second c r u i s e ,  the c u r r e n t meter.  eastward  entering  distributions.  prevailed,  layers,  Narrows  identified  Such a s i t u a t i o n would  Certainly  known t h a t  s i t e of  penetrates  time of  a homogeneity  e n t e r s t h e Arm a s a u n i f o r m section at  the water  be r e c a l l e d t h a t  cross-section.  c a n be  outflowing  from the p r o p e r t y  b a s e d on t h e a s s u m p t i o n o f inflow  in question  cruises.  e s t i m a t e s w e r e made.  Secondly,  entire  interval  to  Such  Indian  velocities Ind  variation  estimated  w i t h volumes  0  from  the  calculated  Agreement better  than f o r  from c u r r e n t s  between  volume  estimates for  a month e a r l i e r , w i t h  and f r o m p r o p e r t i e s  10 m and 15 m s u r f a c e inflow velocity intruded waters, surface outflow  b e i n g 1.37  layer depths.  through and/or  the  inflow  variation  could r a t i o n a l l y  ratios  the  February period  between volumes and 0 . 9 2  Some c o m b i n a t i o n  10  calculated  respectively  for  of  in  variation  c r o s s - s e c t i o n , exchange between  is  of  recently  and 15 m i n t h e d e p t h  e x p l a i n these observed  of  differences.  1 2 1  CHAPTER 7 SUMMARY 7.1  Summary  In S e c t i o n project a)  of Major  1.1  and I n d i a n  of the large scale  Arm t h r o u g h  salinity  and oxygen  to infer  qualitative  First  c)  deep w a t e r  spatial exchange  exchange were  Analysis temperature,  salinity,  a 93-day  From 11  3 t o 10 h o u r s ,  with  and temporal between  scales  Burrard  Inlet  CSTD c a s t s t a k e n o y e r and o x y g e n  and I n d i a n  currents  interval  intervals  d i s t r i b u t i o n data a t t h e mouth  through  in  Burrard  temperature,  distributions.  mid-winter  Arm, i f  Burrard  Inlet  taken of  over  such  i n Chapter  hours,  a period  I n d i a n Arm  goals.  observations  stations  At a l l s t a t i o n s ,  o f a few  mid to l a t e w i n t e r ,  of these stated  consideration i s given  locations).  in  processes i n  associated with  t i m e - s e r i e s o f CSTD c a s t s s p a n n i n g  flow at various  tidal  concerning mixing  a synopsis of the major  short  changes  from the a n a l y s i s of property  l a r g e d e g r e e s a t i s f i e d t h e demands provides  c i r c u l a t i o n pattern  a n a l y s i s of annual  information  and n e a r - b o t t o m  recorded over  station  research  observed.  of s e r i a l  18 m o n t h s ,  tidal  stated for this  distributions.  and Second Narrows  to estimate  summary  objectives  were:  Inlet  of  the three major  to describe features  b)  Observations  have The  to a  following  and c o n c l u s i o n s .  intervals  of  3 to the e f f e c t s  (see Figure  1.1  changes o f p r o p e r t i e s  flow are i d e n t i f i a b l e to at least 3 m depth.  from of  for associated  During  ebb t i d e  122 through  First  Narrows,  appears to extend Atkinson.  effects less  along the North Shore to at  Towards  t h e ebb f l o w of  a shallow narrow.westwards  the southern side of  is evidently  tidal  i n s i d e (at  (approximately possibly  10 m ) .  l e a s t to  sill  Between F i r s t  changes of  In  contrast,  temperature  the s u r f a c e l a y e r . on p r o p e r t y  at  t h e mouth o f  and s a l i n i t y d u e t o  Grey,  the  ranges being c o n s i s t e n t l y influence waters  i n both narrows: 50 m, w e l l  Point  Point  Narrows,  t o much  Narrows ebb f l o w s  t o be a s s o c i a t e d w i t h an a n t i c l o c k w i s e d e e p e d d y .  depths.  seem  Significant  just  i n s i d e each  i n excess of  the 14-18  m  I n d i a n Arm no s i g n i f i c a n t s i n g l e t i d e s extend  A significant conclusion i s that  beneath  short-term  d i s t r i b u t i o n s a s s o c i a t e d w i t h t i d e s are small  effects  compared  with  fluctuations.  The a n n u a l temperature  cycle of  changes i n the d i s t r i b u t i o n of  and s a l i n i t y i n t h e o u t e r  dominantly  c o n t r o l l e d by F r a s e r  North Arm.  A s u r f a c e tongue of  along Point  G r e y on f l o o d i n g t i d e s .  suggest the occasional the v i c i n i t y of  Point  The a n a l y s i s o f distribution  data  property  harbour west of  River water,  surface  First  presumed t o  t h i s f r e s h water  ebb f l o w s a l o n g t h e N o r t h S h o r e .  seasonal  tides  First  and S e c o n d N a r r o w s ,  incoming waters mixed to depths of  seasonal  At  20 m) t h a n o u t s i d e t h e  mixing during flood tides i s evident the  h a r b o u r mouth o f f  mixing are evident with property Ebb  jet  l e a s t the y i c i n i t y of  b r o a d e r and d e e p e r .  i n s i d e than o u t s i d e the Narrows.  greater depth  the  flowing surface  Narrows  enter from  is the  e n t e r s on t h e s o u t h  There i s c l e a r l y concentration  side of  I n a d d i t i o n , e v i d e n c e was p r e s e n t e d  i n t r u s i o n of  dense water masses from the west  to in  Atkinson.  18 m o n t h s o f  in Burrard cycles  Inlet  temperature,  s a l i n i t y , and  oxygen  and I n d i a n Arm y i e l d e d a p i c t u r e  and an o v e r v i e w o f  c i r c u l a t i o n s through  the  of  123 system.  The  seasonal cycles  accord w i t h the annual occasionally to  of  a i r and w a t e r  cycle of  solar radiation.  Extremes  m o d e r a t e d due t o m i x i n g .  through  in  ranges of ranges at  50 m d e p t h  At  in  9.5°C,  200 m d e p t h  6.5°  to  runoff  being the dominant f e a t u r e .  during  i t s p e a k i n May t o e a r l y J u l y inside First  1 2 . 5 ° C and 7 . 5  Strait  of  Georgia water,  surface s a l i n i t i e s water are f e l t  of  Narrows.  to  to  harbour  Strait  of  and  11.5°C. during  the  7.5°C.  p r i m e i m p o r t a n c e as f a r Outside  the narrows,  The  e f f e c t s of  harbour,  east  salinities  Even w i t h t h e w i n t e r  27°/oo.  influx maximum  Fraser  River  are r e s t r i c t e d  brackish surface outflow  near Second Narrows  these harrows.  ranges at  same d e p t h  depth:  when r i v e r d i s c h a r g e i s much r e d u c e d ,  W i t h i n the  and  River discharge, p a r t i c u l a r l y  i s of  from  and has i n c r e a s i n g i m p o r t a n c e  Subsurface s a l i n i t i e s  i n the  harbour  show  Georgia water from the approaches, i n c r e a s i n g l y  m o d i f i e d by m i x i n g i n p a s s a g e t h r o u g h Annual  between 4 °  by r u n o f f and by p r e c i p i t a t i o n , w i t h Fraser  reach only about  I n d i a n Arm i s e v i d e n t  influences  of  t o a l l d e p t h s a s a b s o l u t e maximum s a l i n i t i e s  to about 3 0 ° / o o .  to the east of  somewhat  temperatures  7.0°  d r o p as low as 6 t o 7 ° / o o d u r i n g f r e s h e t . of  drop  I n d i a n Arm d u r i n g M a r c h .  i n Indian Arm,  is controlled jointly  as t h e r e g i o n j u s t  harbour are  i n the approaches, the c e n t r a l  survey v a r i e d only m a r g i n a l l y from about  Salinity  temperatures  temperature decrease s u b s t a n t i a l l y with  I n d i a n Arm a r e 6 . 5 ° t o  respectively.  the  in  l a t e summer and  Coldest surface temperatures  5°C were r e c o r d e d i n low s a l i n i t y w a t e r  typical  Surface  exceed 20°C i n the approaches i n mid to  near 5°C i n w i n t e r .  Seasonal  temperatures are both  First  and t h e n Second  50 m b e t w e e n t h e n a r r o w s a r e 28 t o  i n s i d e Second N a r r o w s ,  r a n g e s a r e 26 t o  Narrows.  30°/oo while at 28.5°/oo.  Within  the  124 Indian  Arm,  runoff  s e a s o n and r i s e  at  surface s a l i n i t i e s  200 m d e p t h  to about  biological  and by d e t r i t a l  to  though  be d o m i n a t e d  coupled with  i n the  relatively  except  in  fresh  Second Narrows. First  Narrows.  Salinities  27.7°/oo.  between  be c o n t r o l l e d near  the  by  surface,  I n d i a n Arm  oxygen seem  from the  f l o w down t h e  Strait  across the  Georgia.  estuarine characteristics  shallow  Indian  of  sills.  surface  Arm s i l l .  It  t h e Arm and may be c l e a r l y  Further mixing  ensues  inlet  at  layer  it  appears traced  these narrows  and  Narrows.  is progressively  occurs.  normally  in a fresh outflowing  outside  freshened  First  high  Arm s y s t e m i s b a s i c a l l y  t h e more d o m i n a n t  Arm  As d e n s e w a t e r , e n t e r i n g it  Inlet/Indian  the s e r i e s of  Indian  as b r a c k i s h s u r f a c e w a t e r  again at  i n the  fall  exchange.  which enter  m i x e s w i t h more s a l i n e w a t e r  almost to  to  are generally  c y c l e assumed t o  surface waters  Indian Arm,  leaves  27.1  atmospheric exchange  winter  Burrard  a r e o b s c u r e d by m i x i n g o v e r  As w a t e r  low r u n o f f .  from about  Changes  the  p a r t i a l l y c o n t r o l l e d by t h e s e same p r o c e s s e s ,  o v e r l y i n g more s a l i n e w a t e r s However,  times of  Inlet  at depth.  by a d v e c t i v e  Circulation estuarine:  in Burrard  consumption  as l o w as 2 ° / o o d u r i n g  survey  and r e f l e c t a s e a s o n a l  production  distribution,  to  25°/oo at  changed d u r i n g the  Oxygen c o n c e n t r a t i o n s 4 and 7 m l / 1 ,  drop  Narrows  a s downward  A s i m i l a r f r e s h e n i n g at depth  a t d e p t h moves mixing of  up t h e  near s u r f a c e  i s more i n t e n s e a c r o s s  inlet, water  Second  Generally influences water  of  tidal  i n t h e r e g i o n between t h e n a r r o w s , f r e s h water  inflow at  outflow from  Indian Arm,  the s u r f a c e a c r o s s F i r s t  and s t r o n g m i x i n g w i t h more s a l i n e w a t e r s Narrows,  environment.  (the  A further  in a less  a p p r o a c h e s ) where d e n s i t i e s a t  brackish density  This  i s to  (oscillating), and S e c o n d and c o o l e r  complicated estuarine  owing to  First  Narrows  is  enter  the surface are often the  i n f l u e n c e of  Fraser  from a f j o r d  s u r f a c e water  e n t e r s a c o a s t a l r e g i o n where  i s much c l o s e r  to that  of  the flow through  of  Burrard  That a strong e s t u a r i n e - t y p e c i r c u l a t i o n  O c t o b e r 1974,  ( S e c t i o n 5 . 3 and C h a p t e r  waters from j u s t o u t s i d e  penetrating  i n t o the Arm,  the c r u i s e s  of  took  place at depth,  100 m d e p t h . evident.  to  I n d i a n Arm.  of water  During  across the s i l l  to about  intensifies.  September  the  winter  water  and  early  regularly  70 m d e p t h .  a more s u b s t a n t i a l  with these denser waters  At  watersheds,  i n t r u s i o n o f deep  I n d i a n Arm w e r e  16 and November 7 ,  penetrating at  Between  intrusion least  to  A c o r r e s p o n d i n g p e r s i s t e n t f r e s h e r s u r f a c e o u t f l o w was  During January,  intrusions of  October  6).  Inlet  p e r s i s t e d through  1 9 7 4 - 1 9 7 5 m u s t be i n f e r r e d f r o m t h e o b s e r v e d  the  t h e open o c e a n .  the e s t u a r i n e nature  I n d i a n Arm  200 m t o o k For  than  River  i s h i g h e s t f r o m t h e C a p i l a n o and S e y m o u r  into  an  lower  t h o s e t i m e s when r u n o f f  of  that  be c o n t r a s t e d w i t h t h e more t r a d i t i o n a l s i t u a t i o n w h e r e  surface outflow of  fresh  d e v i a t i o n from a simple e s t u a r i n e flow  those of the o u t f l o w i n g waters water.  Narrows  across both F i r s t  s u r f a c e waters which pass to the west through area  relatively  y i e l d s u r f a c e w a t e r s w h i c h a r e a l w a y s more s a l i n e  i n summer t h a n w o u l d be e x p e c t e d  125  the c o n f l i c t i n g  the f i r s t of place,  purposes of  contained in Burrard  a series  o f m a j o r deep  replacing approximately comparison, i t  Inlet  water  55% o f  i s noted t h a t  f r o m t h e H a r b o u r mouth a t  also  the  the  volume  volume  Point  Grey/  126 P o i n t A t k i n s o n t o P o r t Moody in  I n d i a n Arm n o r t h o f  Inlet of  l y i n g east of  this total.  its sill.  First  Thus f o r  a s u b s t a n t i a l volume of Narrows.  i s e f f e c t i v e l y t h e same a s t h a t The v o l u m e o f  Narrows  (excluding  that  contained  portion of  I n d i a n Arm)  i s about  Narrows,  an e q u a l volume o f  i n an o u t f l o w i n g  surface layer.  demands s u b s t a n t i a l v o l u m e e x c h a n g e b e t w e e n w i t h the o r i g i n of approaches,  i n t r u d i n g waters  less  Such a major exchange f u r t h e r  concerning s i g n i f i c a n t net  record  at  l e a s t 80% o f  i n t e r v a l J a n u a r y 27  near the  c u r r e n t s over  Allowing for  c r o s s - s e c t i o n or p o s s i b l y f o r deduced from the p r o p e r t y a r g u e d t o be c o m p a t i b l e .  the  the  volume  February  the  Narrows surface.  for  the  volume exchange t h a n t h e  d i s t r i b u t i o n s , t h e s e volume e s t i m a t e s  the  January  to w i t h i n at  v a r i a t i o n i n f l o w speed through greater  in  i n f l o w volumes d e r i v e d from I n d i a n Arm s i l l ,  21,  above  i n t r u s i o n v o l u m e s made f r o m c h a n g e s  and F e b r u a r y p e r i o d s m e n t i o n e d a b o v e y i e l d e d a g r e e m e n t 2.5.  to  at depth across F i r s t  d i s t r i b u t i o n s with estimates of  a f a c t o r of  Inlet,  s u p p o r t s t h e c o n c l u s i o n s drawn  transport  estimates of  of near-bottom  evidence  l e a v i n g the system i n a  a c c o m p a n i e d by a c o r r e s p o n d i n g n e t v o l u m e o u t f l o w  property  The  l e a s t as f a r w e s t as  inflow suggest that  I n d i a n Arm was r e p l a c e d d u r i n g t h e  Comparison of  sills,  layer.  Further estimates of  1975.  First  I n d i a n Arm and B u r r a r d  being at  and w i t h l a r g e v o l u m e s o f w a t e r  westward f l o w i n g s u r f a c e  of  Arm,  dense w a t e r must have e n t e r e d f r o m o u t s i d e  d e n s e w a t e r w h i c h was d i s p l a c e d m u s t h a v e p a s s e d o v e r a l l t h e First  27%  a 55% v o l u m e e x c h a n g e t o o c c u r i n I n d i a n  Likewise to preserve c o n t i n u i t y ,  including  Burrard  the  worst inflow  minimum were  127 As t h e of  c u r r e n t meter  i n t r u s i o n volume  noted,  however,  1975.  Rough  volume  exchanges  the  periods  inflow  it  analysis,  various  the  5.26,  5.27  possible.  into April  and 5 . 2 9  suggest  t o M a r c h 26 and M a r c h 26 t o A p r i l  comparable  to  through 5-10  a further  that  still,  the western  two m o n t h s  Further  questions  those exchanged  It  through  and c e n t r a l  from  29,  of  late  January  haye p e r s i s t e d i n t h e  have  harbour,  and  layer  February.  over  1975.  the  inflowing  must  Similarly,  surface  layer.  Investigations of  this  remain,  and m e a s u r e m e n t .  It  nature  and p e r f o r m i n g  the answers  i s suggested  the  subsequent  to which r e q u i r e  that  further  p r i n c i p a l among  these  following:  What i s t h e a c t u a l  pattern modified  nature  of  f l o w a c r o s s the  How i s t h e o v e r a l l  by t i d a l  flow  through  sills  through  mixing relax  the v a r i o u s  narrows?  and a l l o w t h e p a s s a g e o f  m a s s e s a s was r e c o r d e d i n J u l y  1974?  at  First  and  estuarine circulation these r e s t r i c t e d channels?  What i s t h e a c t u a l m e c h a n i s m w h i c h c o n t r o l s m i x i n g of waters  was  that  s o u r c e w a t e r s must  cm/sec i n t h e deep  o u t f l o w must  and Second Narrows?  2)  were not  comparisons  l e a s t 3 0 - 4 0 % and 4 0 - 5 0 % r e s p e c t i v e l y o c c u r r e d  speeds of  volume  quantitative  exchange d i d c o n t i n u e  Figures  conducting a study  observation  e n s u i n g months  c a n be i n f e r r e d  Potential  After  1)  are  persisted for  7.2  at  the approaches  significant  are  of  from  F e b r u a r y 21  t h a t mean i n f l o w have  deep w a t e r  estimates  period,  come f r o m  estimates for  that  As t h e s e volumes  r e c o r d e n d e d on M a r c h 7 ,  i n the  passage  Under what c o n d i t i o n s b a s i c a l l y unmodified  does  water  128 In  addition  control  to density  i n f l o w of  differences,  near-bottom  what are  waters  into  vary?  Under what c o n d i t i o n s does o u t f l o w  depth,  thereby y i e l d i n g periods of  periods of  net  i n f l o w along the  t h e mechanisms  Indian  How do  f r o m t h e Arm o c c u r  net outflow  bottom?  Arm?  between  which these at  extended  129  LITERATURE.CITED  Atmospheric Environment S e r v i c e . 1974-1975. Monthly Record, M e t e o r o l o g i c a l Observations i n Canada. Environment Canada, Toronto. B e l l , W . H . , 1973. The E x c h a n g e o f Deep W a t e r i n Howe S o u n d B a s i n . Pac. Mar. S c i . Rept. 73-13, Mar. S c i . D i r e c t . , Pac. R e g . , Environment Canada, V i c t o r i a , B.C. B e l l , W . H . , 1974. O c e a n o g r a p h i c O b s e r v a t i o n s i n Howe S o u n d 1 9 7 2 . Pac. Mar. S c i . Rept. 74-7, Mar. S c i . D i r e c t . , Pac. Reg. Environment Canada, V i c t o r i a , B.C. B u c k i n g h a m , W . R . , 1976. A Heat Budget A n a l y s i s o f P e n d r e l l Sound. M.Sc. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y of B r i t i s h C o l u m b i a , V a n c o u v e r , B . C . 63 p . Buckley, J.R. 1977. The C u r r e n t s , W i n d s and T i d e s o f N o r t h e r n Howe Sound. Ph.D. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y of B r i t i s h C o l u m b i a , V a n c o u v e r , B . C . 228 p . Campbell, N.J. 1954. A s t u d y o f L a t e r a l C i r c u l a t i o n i n an Ph.D. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y of Columbia, Vancouver, B.C.  Inlet. British  Canadian Hydrographic S e r v i c e . 1973. Atlas of Tidal Current Charts Vancouver Harbour B r i t i s h Columbia. T i d a l C u r r e n t P u b l i c a t i o n No. Can. Hydrogr. S e r v . , Mar. S c i . B r . , Dept. E n v i r o n . , Ottawa. Canadian Hydrographic S e r v i c e . 1975. 5_:Juan de F u c a and G e o r g i a S t r a i t s . B r . , Dept. E n v i r o n . , Ottawa.  C a n a d i a n T i d e and C u r r e n t T a b l e s Can. Hydrogr. S e r v . , Mar. S c i .  C a r t e r , N.M. 1934. P h y s i o g r a p h y a n d O c e a n o g r a p h y o f Some B r i t i s h Fiords. P r o c . 5 t h P a c . S c i . C o n g r e s s , 1933 1_:721-733. Farmer, D.M. of Alberni Vancouver,  30.  Columbia  1972. The I n f l u e n c e o f t h e W i n d on t h e S u r f a c e W a t e r s Inlet. Ph.D. T h e s i s , U n i v e r s i t y B r i t i s h Columbia, B . C . 92 p .  Gilmartin, Malvern. 1962. Annual C y c l i c Changes i n t h e P h y s i c a l Oceanography o f a B r i t i s h Columbia F j o r d . J . F i s h . Res. Bd. Canada, 19(5):921-974. L a f o n d , C. 1975. Deep W a t e r E x c h a n g e i n B u t e I n l e t , B r i t i s h C o l u m b i a . M.Sc. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y of B r i t i s h Columbia. Vancouver, B.C. Lazier, J.R.N. 1963. Some A s p e c t s o f t h e O c e a n o g r a p h i c S t r u c t u r e o f the J e r v i s I n l e t System. M.Sc. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B . C . 54 p . M a c N e i l l , M.R. 1974. The M i d - D e p t h T e m p e r a t u r e M i n i m u m i n B . C . Inlets. M.Sc. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C.  130 McHardy, R.A. 1961. A S t u d y o f t h e Taxonomy and Some A s p e c t s o f t h e Ecology o f Marine Ostracods i n the P l a n k t o n o f I n d i a n Arm, B r i t i s h Columbia. M.Sc. Thesis. I n s t i t u t e of Oceanography, U n i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C. P a c i f i c Oceanographic Group. 1951. Data Record - F r a s e r R i v e r E s t u a r y P r o j e c t , 1950. J o i n t C o m m i t t e e on O c e a n o g r a p h y : 489 p . P i c k a r d , G.L. 1961. Oceanographic Features of I n l e t s i n the Mainland Coast. J . F i s h . Res. Bd. Can. 18(6):907-999.  B.C.  P i c k a r d , G.L. 1975. A n n u a l and L o n g e r Term V a r i a t i o n s o f D e e p w a t e r P r o p e r t i e s i n the C o a s t a l Waters o f Southern B r i t i s h Columbia. J . F i s h . Res. Bd. Can. 32(9):1561-1587. R a t t r a y J r . , M. 1962. Deep-Sea R e s e a r c h .  Interpolation 19:25-37.  Errors  and O c e a n o g r a p h i c  Sampling.  R e g a n , L. 1968. E u p h a u s i a P a c i f i c a and O t h e r E u p h a u s i i d s i n the C o a s t a l Waters o f B r i t i s h C o l u m b i a ; R e l a t i o n s h i p s to Temperature, S a l i n i t y and O t h e r P r o p e r t i e s i n the F i e l d and L a b o r a t o r y . Ph.D. T h e s i s . I n s t i t u t e of Oceanography, U n i v e r s i t y of B r i t i s h Columbia. Vancouver, B.C. Reiniger, R.F., Application  and R o s s , C K . to Oceanographic  1968. Data.  A Method o f I n t e r p o l a t i o n w i t h Deep-Sea R e s e a r c h . 15:185-193.  Shan, Kuo-Cheng. 1962. S y s t e m a t i c and E c o l o g i c a l S t u d i e s on C o p e p o d a i n Indian Arm, B r i t i s h Columbia. M.Sc. Thesis. Institute of Oceanography, U n i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C. T a b a t a , S. 1971. A B r i e f Oceanographic D e s c r i p t i o n of the Waters of B u r r a r d I n l e t and I n d i a n A r m . . A p p e n d i x D o f The B u r r a r d I n l e t - Howe Sound A r e a , P r e l i m i n a r y D e s c r i p t i o n of E x i s t i n g Environmental C o n d i t i o n s . M a r . S c i . D i r e c t . , P a c . R e g . , R e p t . F i s h e r i e s and E n v i r o n m e n t , C a n a d a . T a b a t a , S . and P i c k a r d , G . L . I n l e t , B r i t i s h Columbia.  1957. The P h y s i c a l O c e a n o g r a p h y o f B u t e J . F i s h . Res. Bd. Canada, 14(4):487-520.  Tully, J.P. 1949. O c e a n o g r a p h y and P r e d i c t i o n o f in Alberni Inlet. B u l l . F i s h . Res. Bd. Canada, W a l d i c h u k , M. 1965. 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B r i t i s h Columbia I n l e t s C r u i s e s 1975.  of  British  132 APPENDIX  I  PHOTOGRAPHIC DYE-TRACKING STUDY  Introduction In  the f a l l  developed First  i n an a t t e m p t t o r e m o t e l y  Narrows.  applied, over  base f o r t h e g e n e r a t i o n  and t h u s  the channel,  The L i o n ' s  fixed  The technique  velocity  and w i t h  resolution  i t followed  that  "Fisheye"  required  150° to adequately  cover  that  to s a t i s f y  wide  angles  Because o f t h i s w i d t h - o f - f i e l d , lenses of t h i s  sort  images a r e r e n d e r e d the consequent  generally  h a v e t o h a v e an  "fisheye"  of view,  lengths  lenses  recti linearity  demand.  o f 16 mm o r  typically cannot  have s u c h pronounced  follow  Surveying  this width-of-field  a s c i r c u l a r on t h e f i l m .  distortions  With  530 m w i d t h  the scene.  only  l e n s e s f o r 35 mm f o r m a t h a v e f o c a l  They have e x t r e m e l y  spans  d i s t a n c e a t 61 m.  t h e chosen l e n s would  of  f o r the temporal  desired across the f u l l  t h e 35 mm f o r m a t w o u l d be a b l e  of l i n e s  Gate B r i d g e which  the camera-to-subject  for  lenses  data.  of cross-channel  a v a i l a b i l i t y o f l e n s e s i t was a p p a r e n t  that  application  data.  the  Thus,  precluded  to describe' the  t h e r i g i d camera p l a t f o r m  angle of view o f a t l e a s t  wider.  through  was s u c c e s s f u l l y  much u s e f u l  i s included only  dye i n the narrows.  constraint  shorter.  surface currents  Technique  Narrows p r o v i d e d  this  t e c h n i q u e was  i t was d e s i r e d t o a c q u i r e t i m e - s e r i e s p h o t o g r a p h s  fluorescent  analysis  tidal  constraints  a sample o f t h e r e s u l t i n g  As a d a t a profiles,  measure  long time t o generate  discussion then,  and t o p r e s e n t  of  t i m e and p r i o r i t y  a sufficiently  Photographic  dye-tracking  In February o f 1976, t h e procedure  however,  following  the  of 1975, a photographic  180° or be p r e s e r v e d .  barrel  F o r some  explicit projection  distortions  "fisheye" formulae,  133 thus making p o s s i b l e the a n a l y t i c a l r e c t i f i c a t i o n of image back t o  The Nikkor.  projection  h a s an a n g l e o f  view of  220°  was a 6 mm f / 5 . 6  and a d o p t s  the  Fisheye  equidistant  • (9)  (1)  d = distance to  image  centre  constant  9 = zenith (J.D.  the present study  formula:  (C)  C =  "fisheye"  format.  lens selected for It  d  rectilinear  the  Cooper,  angle.  Nikon  Nikkormat  Handbook p . 6 - 5  (Amphoto,  N.Y.))  Transformation To d e v e l o p from the  a n a l y t i c a l l y the coordinate t r a n s f o r m a t i o n  "fisheye"  image t o  s u r f a c e v e r t i c a l l y beneath as i n F i g u r e  The  an u n s e a l e d r e a l f r a m e the  the  sea  (d1,^1)  I-l(a).  of  the  projection formula  (1)  immediately:  (2)  $ = cj>  Actual  centred at  camera, consider a point  bearing-preserving property  specifies $  F ( d 1 ,cb') =  r a n g e D c a n be e x p r e s s e d  D = H tan 6 = H tan  (£)  (Figure  f o r 6 < |-  I-l(b))  as: (3)  (D,$)  134 The  constant  C i s evaluated  f r o m t h e maximum d i m e n s i o n s  of  the  "fisheye'  image, r' 6 max thus  determining  F  (d',4,')  Finally, 7s  we  (4)  110 the  basic  = (D,$)  converting  transformation:  =[.H  to  the  (  ^  tan (^-  (X,Y)  • 110°) ,  frame  ]  (5)  and i n t r o d u c i n g a s c a l e  factor  have:  X =  t  a  n  ^  /(l (^t  -110°)  (6)  +  = ML  Where  the  r e m a i n i n g unknowns  "fisheye"  Field  x',  y',  and r 1  can a l l  be m e a s u r e d  from  the  image.  Operation The  physical operation  mounting  of  painter's  a Nikon  trolley  of  photographing  F-250 m o t o r - d r i v e  beneath  the  system,  c a r deck of  the  t h e dye with  lines  the  Lion's  on a  Gate B r i d g e .  The  a x i s was o r i e n t e d n o r m a l  to  the water  filters  057  to  enhance the w a t e r - d y e  black-and-white  Lines across  the  intervals  the  6 mm l e n s ,  optical  o r R60 w e r e e m p l o y e d  involved  surface.  Built-in  lens  contrast  on  the  images.  o f 20% channel as t h e y  (by w e i g h t )  Rhodamine  from a small passed under  skiff the  WT s o l u t i o n w e r e  introduced  and were p h o t o g r a p h e d  bridge.  at  fixed  time  135 Analysis  and P r e s e n t a t i o n  Position The  of  Results  Transformation  initial  s t e p s o f a n a l y s i s were t h e s o r t i n g ,  s c r e e n i n g o f t h e s e t s o f images from  individual  those which d i s p l a y e d best c o n t r a s t . printed  i n 10 x 10 i n c h f o r m a t w i t h  overlaid,  thus  e s t a b l i s h i n g uniform  documentation,  dye l i n e s i n o r d e r  These s e l e c t e d s e t s were principal point  and t o choose  then  and f i d u c i a l  marks  r e f e r e n c e s f o r t h e measurement  of  r a n g e s and b e a r i n g s .  The  p o s i t i o n o f t h e l e a d i n g e d g e o f t h e d y e l i n e on e a c h s u c c e s s i v e  p r i n t was m e c h a n i c a l l y d i g i t i z e d . transformed Figures four  via relations  I-2(a)  through  particular lines,  time increment figure  one h a l f  hour  ebb on t h e a f t e r n o o n  Velocity  i n f o r m a t i o n was t h e n  along with  corresponding t i d a l  information.  each s e t of l i n e s but v a r i e s  follow a tidal  sequence from  high s l a c k to approximately of February 9,  one h a l f  Figures  each p l o t ,  adjusted point  The  from approximately  hour b e f o r e  full  Calculations  I-2(a)  through  I-2(d)  were  generated  a single cross-channel p r o f i l e  t h e mean h o r i z o n t a l were then  of  1976.  To f a c i l i t a t e t h e c a l c u l a t i o n o f v e l o c i t i e s , p l o t s to  coordinates.;  I - 2 (d) p r e s e n t t h e s e q u e n t i a l t r a n s f o r m e d p o s i t i o n s  The f i g u r e s  after  coordinate  (6) to y i e l d t h e r e c t i l i n e a r ( X , Y )  i s uniform within  to f i g u r e .  This  dye l i n e p o s i t i o n .  created with  the exact  t o match t h e apparent  corresponding  at a scale of 1:1500,  l i n e was s e l e c t e d  approximating  A set of "long-channel"  orientation  o f each p a r t i c u l a r  axiis axis  flow d i r e c t i o n at the corresponding  on t h e c r o s s - c h a n n e l p r o f i l e  i n t e r s e c t i o n s w i t h each s e q u e n t i a l  line.  Digitization  dye l i n e y i e l d e d  For  sampling  of the axis  a series of spatial  .136 intervals In  representing  t h i s manner,  along the  distance travelled  mean v e l o c i t i e s w e r e  profile  mean v e l o c i t y  the  line.  profiles  Figure for  1-3  the f o u r  i n one t i m e  calculated for i s the data  increment.  discrete  presentation  of  points  the  resultant  sets.  Summary A wide f i e l d of dictated lines images plots  the  use of  through via  the  First  view  and l i m i t e d c a m e r a - t o - s u b j e c t  a "fisheye" Narrows.  equidistant  and v e l o c i t y  profiles  lens to  photograph  Transformation projection  of  the  passage of  distorted  formula y i e l d e d  in rectilinear  distance  "fisheye"  sequential  coordinates.  dye  position  137  FIGURES  (a) BURRARD INLET  Figure  1.2  Longitudinal  depth p r o f i l e s  of  (a). Burrard  Inlet  and ( b )  Indian  Arm  140  (hours)  13 14  Figure  3.1  15  16  17  18  19  20  21  22  23  24 13  Empirical t i d a l curves (representative of Burrard I n l e t t i d e s ) showing " t i d a l b i n " d e f i n i t i o n s  18  19  —i 0900  Figure  *=  3.2  (  19  21  1 1100  i  21  22  1 1300  T i m e - d e p t h s e c t i o n s o f (a) s a l i n i t y (b) t e m p e r a t u r e a t Van 1 1 - 1 , August  22  -r—• 1500  and 28,  1975  2 8.0 •  SALINITY %o ST N-VAN 11 O900  Figure  3.3  -2BO  1100  P S T 2 8 AUGUST 1975 I  T i m e - d e p t h s e c t i o n s o f (a) ( b ) t e m p e r a t u r e a t Van 1 1 ,  00  s a l i n i t y and A u g u s t 2 8 , 1975  1500  Figure  3.4  T i m e - d e p t h s e c t i o n s o f (a) s a l i n i t y and (b) t e m p e r a t u r e a t Van 1 1 - 5 , A u g u s t 2 8 ,  1975  Figure  3.5  T i m e - d e p t h s e c t i o n s of (a) s a l i n i t y ( b ) t e m p e r a t u r e a t Van 1 1 - 8 , A u g u s t  and 28,  1975  145  Figure  3.6  C o m p a r a t i v e t e m p e r a t u r e and s a l i n i t y p r o f i l e s f r o m B u r r a r d I n l e t A p p r o a c h e s , J u l y 2 5 , 1975  SALINITY STN-- V A N  9/ /oo 17 AUGUST 1975  PST  1900  TEMPERATURE c S T N : V A N 17 u  PST 1100  0900  Figure  3.7  Time-depth August 26,  "300  sections 1975  of  26 AUGUST 1975 1500  (a)  salinity  and  1900  1700  (b)  t e m p e r a t u r e a t Van  17, £ CTl  Figure  3.8  Time-depth sections A u g u s t 2 6 , 1975  of  (a)  salinity  and ( b )  t e m p e r a t u r e a t Van  24,  148  Figure  3.9  Time-depth s e c t i o n s o f (a) (b) t e m p e r a t u r e a t Van 2 7 ,  s a l i n i t y and August 27, 1975  sfc  20  19  20  21  21  21  22  22  22  X .  12  \ 2ao  18  SALINITY %o STN:VAN 34  _ ^ P S T 27 AUGUST 1975 1400  idoo  sfc  1200  20  19  26J0  20  21  21  21  22  22  13.0  12.5  X  fc Ul  a  12  12.0_  TEMPERATURE *b STN'. VAN 34 PST 27 AUGUST 1975 1400 1200  idoo  Figure  3.10  T i m e - d e p t h s e c t i o n s o f (a) (b) t e m p e r a t u r e a t Van 3 4 ,  s a l i n i t y and August 27, 1975  22  sfc  20  X Ul O  ^2^  18H  SALINITY S T N :  INDO  PST 27 AUGUST 1975 1300  1100  20 SfCn  21  1500  22  22 13.5^  -13/}  6H  -12.5-  X Ul  a  124  18H  T E M P E R A T U R E S T N :  IND  1100  Figure  3.11  °c  0 PST 27 AUGUST 1975 ' 1300  1500  T i m e - d e p t h s e c t i o n s o f (a) s a l i n i t y and ( b ) t e m p e r a t u r e a t I n d 0 , A u g u s t 2 7 , 1975  Figure  3.12  T i m e - d e p t h s e c t i o n s o f (a) s a l i n i t y and ( b ) t e m p e r a t u r e a t Van 1 1 , A u g u s t 1 9 , 1975  Figure  3.13  Time-depth sections of ( b ) t e m p e r a t u r e a t Van  ( a ) s a l i n i t y and 11, S e p t e m b e r 3 ,  1975  153 (a)  700  LU  600H  500  400  E E c  300  o  P 200 5.  a- 100  M  -i  J  J  A  1974  1  S  1  O  1  N  1—:—i  D  J  • Buntzen Lake A Point Grey  F  1  1  1  1  M  A  M  J  1975  l  l  J  A  i —  S  1  i  1  1  O  OPort Moody Gulf Refinery + Vancouver Int. Airport  (b) 20l  16  • '2 o <D |  <  8  4  1  M  1  J  1  1  J A 1974  Figure  4.1  i  S  O  1  1  N  D  1  1  J  F  i  1  r  M  A  M  i  J  1  1  J A  1975  S e a s o n a l v a r i a t i o n o f (a) p r e c i p i t a t i o n and (b) a i r t e m p e r a t u r e a t s t a t i o n s s u r r o u n d i n g Burrard Inlet  i  1  S O  1  154  Figure 4.2  S e a s o n a l v a r i a t i o n o f ( a ) m o n t h l y mean w i n d s p e e d a n d ( b ) d a i l y mean w i n d s p e e d a t s t a t i o n s s u r r o u n d i n g Burrard Inlet  155  Figure  4.3  Seasonal v a r i a t i o n of monthly r u n o f f from (a) F r a s e r R i v e r a t M i s s i o n and (b) C a p i l a n o R i v e r , Seymour R i v e r and B u n t z e n Power Houses  Figure  5.1(a)  Figure 5.1(b)  Station locations i n Burrard I n l e t Approaches  Surface d i s t r i b u t i o n of density (sigma-t) i n Burrard Inlet A p p r o a c h e s , A u g u s t 1 , 1974  Figure  5.2  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and ( b ) t e m p e r a t u r e i n B u r r a r d I n l e t Approaches, August 1, 1974  M i s s i n g page  Figure  5.4  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and (b) t e m p e r a t u r e i n B u r r a r d I n l e t Approaches, February 22, 1975  160  Figure  5.5  S u r f a c e d i s t r i b u t i o n s of (a) s a l i n i t y and (b) t e m p e r a t u r e i n B u r r a r d I n l e t A p p r o a c h e s , May 3 0 , 1975  Figure  5.6  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and ( b ) . t e m p e r a t u r e i n B u r r a r d I n l e t A p p r o a c h e s , June 13, 1975  Figure  5.7  Surface d i s t r i b u t i o n s o f c ( a ) s a l i n i t y and (b) t e m p e r a t u r e i n B u r r a r d I n l e t A p p r o a c h e s , J u l y 2 5 , 1975  163  Figure  5.8  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and (b) t e m p e r a t u r e i n B u r r a r d I n l e t Approaches, August 19, 1975  Figure 5.9  S u r f a c e d i s t r i b u t i o n s of (a) s a l i n i t y and ( b ) t e m p e r a t u r e i n B u r r a r d I n l e t A p p r o a c h e s , September 3 , 1975  Figure  5.10  S u r f a c e d i s t r i b u t i o n s o f (a) s a l i n i t y and ( b ) t e m p e r a t u r e i n B u r r a r d I n l e t Approaches, October 10, 1975  Figure  5.11  Time-depth sections of a t s t a t i o n s ( a ) V a n 11 (e) Ind 2  t e m p e r a t u r e , May 1974 t o O c t o b e r 1975 ( b ) V a n 24 ( c ) V a n 34 ( d ) I n d 1 a n d  Figure 5.12  Time-depth sections of salinity, May 1974 to October 1975 at stations (a) Van 11 (b) Van 24 (c) Van 34 (d) Ind 1 and (e) Ind 2  170  Figure  5.13  Time-depth sections of a t s t a t i o n s ( a ) V a n 11 and (e) Ind 2  o x y g e n , May 1974 t o O c t o b e r 1975 ( b ) V a n 24 ( c ) V a n 34 ( d ) I n d 1  171  172  Figure  5.14  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r B u r r a r d I n l e t , May 1 4 ,  1974  173  Figure  5.15  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , J u l y 17,  1974  175  Figure  5.16  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r B u r r a r d I n l e t , A u g u s t 2 7 ,  1974  177  Figure  5.17  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r I n d i a n A r m , A u g u s t 2 7 ,  1974  180  Figure  5.18  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r I n d i a n A r m , O c t o b e r 1 6 ,  1974  182  Figure  5.19  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r B u r r a r d I n l e t , November 7 ,  1974  183  Figure  5.20  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r I n d i a n A r m , N o v e m b e r 7 ,  1974  Figure  5.21  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , December 5 ,  1974  187  Figure  5.22  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r I n d i a n A r m , December 6 ,  1974  Figure  5.23  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t  salinity January 23,  1975  191  192  Figure  5.24  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r I n d i a n A r m , J a n u a r y 2 3 ,  1975  193  Figure  5.25  L o n g i t u d i n a l s e c t i o n s of (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , F e b r u a r y  19,  1975  195  Figure  5.26  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r I n d i a n A r m , F e b r u a r y 2 1 ,  1975  197  Figure  5.27  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t a n d ( d ) o x y g e n f o r I n d i a n A r m , M a r c h 2 6 , 1975  199  Figure  5.28  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , A p r i l 2 9 ,  1975  201  Figure  5.29  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t a n d ( d ) o x y g e n f o r I n d i a n A r m , A p r i l 3 0 , 1975  Figure  5.30  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , June 1 3 ,  1975  Figure  5.31  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and ( d ) o x y g e n f o r B u r r a r d I n l e t , A u g u s t 1 8 ,  1975  207  Figure  5.32  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y • ( c ) s i g m a - t and (d) oxygen f o r I n d i a n A r m , A u g u s t 1 8 ,  1975  209  Figure  5.33  L o n g i t u d i n a l s e c t i o n s o f (a) t e m p e r a t u r e (b) s a l i n i t y ( c ) s i g m a - t and (d) oxygen f o r B u r r a r d I n l e t , O c t o b e r 9 ,  1975  211  212  4 FEBRUARY  Figure  6.1  5  D e t a i l o f t e m p e r a t u r e and s a l i n i t y r e c o r d s f r o m n e a r - b o t t o m c u r r e n t m e t e r on I n d i a n Arm s i l l , showing i n t e r v a l s of p o s s i b l e instrument malfunction  ZIZ  nz  SI2  Figure  6.3  T i m e - s e r i e s o f t e m p e r a t u r e and s a l i n i t y a t c u r r e n t meter s i l l , December 5 , 1974 t o J a n u a r y 4 , 1975 :•••[  i 1 ii i iii: 1 i l!li •irfiii  : i l l: ! 1  L  iii !  ;  iH!  .i  •  :  \  •1  fi|:- • . j :  %  9  <  8  S( : ji .  lli-  :  : :\ ; ' :  ^; I  I  \4 1  : ":: i:  i iii: ;  i : ::-ii-  •i 1;- 14  % • •  444 •  If-4-l - i - r .  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L  A 1 ^.S  • !'  75/01 7  8  9  10  11  12  13  114 115 116 117 DECEMBER  1  18  19  20  21  _i  22  • • 23  24  25  26  27  28  29  30  31  1  2  3  JANUARY  4  ro t—•  217  CRUISES 74/36 I 5  Figure  75/01 1  1  1  10 15 20 DECEMBER  6.4  1  1  25  30  S 4  75/03 1  1  1  9 14 19 JANUARY  H  24  75/05 75/06 1  1  29  3  1  1  P —  8 13 18 FEBRUARY  i 23  T i m e - s e r i e s o f a v e r a g e d n e a r - b o t t o m c u r r e n t s o n I n d i a n Arm s i l l , D e c e m b e r 5 , 1974 t o M a r c h 7 , 1975  75/08 •  r-"  28 5 MARCH  218  6  4  , DEC. 14 - 27 ' 14 DAYS  DEC. 29 '  '  27  -  J A N . 24  J A N . 27  DAYS  '  '  -  33  MARCH 1  DAYS  '  28n  2  6  J CRUISES  74/36  I  5  75/01 1  1  1  10 15 20 DECEMBER  1  1  25  30  75/03 1  4  1  i  1  9 14 19 JANUARY  75/05 75/06  24  29  1  3  1  i— ^ i  8 13 18 FEBRUARY  23  75/08  •  • ^  28 5 MARCH  Figure 6.5 Time-series of averaged temperature and salinity at current meter site on Indian Arm s i l l , December 5, 1974 to March 7, 1975  219  Figure I-l(b)  Figure 1-1  Geometry of coordinate transformation  220  NORTH VANCOUVER  Figure  1-2  NORTH VANCOUVER  T r a n s f o r m e d p o s i t i o n s o f d y e l i n e s , F e b r u a r y 9 , 1976 a t ( a ) 1147 P S T , ( b ) 1402 P S T , ( c ) 1441 PST a n d ( d ) 1520 PST  Figure  1-3  Cross-channel  velocity  profiles,  February 9,  1976  3.CH  1441 P S T 1520 PST CO  o c  1402 PST  -2.0H Q Lu  UJ  a.  CO UJ  rr  tr  O  1XH  F E B R U A R Y 9 1976  1147 P S T  1030  1845  100 i  200  300 •  CROSS CHANNEL DISTANCE  400 FROM  i  S O U T H S H O R E (m)  500 i  ro ro  

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