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Babbage River delta and lagoon : hydrology and sedimentology of an Arctic estuarine system Forbes, Donald Lawrence 1981

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BABBAGE  RIVER  HYDROLOGY OF  DELTA  AND LAGOON:  AND. SEDIMENTOLOGY  AN A R C T I C  ESTUARINE  SYSTEM  by DONALD M.A.,  THESIS THE  LAWRENCE  University  SUBMITTED  IN  REQUIREMENTS DOCTOR  of  FORBES Toronto,  PARTIAL  1973  FULFILMENT  FOR T H E DEGREE  OF  OF  PHILOSOPHY  in THE  FACULTY  OF  (Department  We  accept to  THE  this  the  GRADUATE of  thesis  OF  Donald  as  conforming  standard  BRITISH  A p r i l  ©  Geography)  required  UNIVERSITY  STUDIES  Lawrence  COLUMBIA  1981  Forbes,  1981  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 f u l f i l m e n t o f the r e q u i r e m e n t s f o r  an advanced d e g r e e a t the 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 , I a g r e e t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and I f u r t h e r agree that permission f o r s c h o l a r l y p u r p o s e s may by h i s r e p r e s e n t a t i v e s .  for extensive  study.  copying of this thesis  be g r a n t e d by the Head o f my Department o r I t i s u n d e r s t o o d t h a t c o p y i n g or p u b l i c a t i o n  o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l l o w e d w i t h o u t written  permission.  Department  nf  Geography  The U n i v e r s i t y o f B r i t i s h Columbia 2075 Wesbrook P l a c e V a n c o u v e r , Canada V6T 1W5 .10  September  .1981  my  i i  ABSTRACT  Inputs,  t r a n s f e r p r o c e s s e s , and s t o r a g e c h a r a c t e r i s t i c s of  water and sediment system  on  the  central  transgressive, Babbage  h a v e been i n v e s t i g a t e d Yukon  microtidal,  Estuary  system  tidal-distributary,  coast.  and  can  i n a 40-km The  high-latitude  be  subdivided  delta-plain,  estuarine  2  setting  is  (69°N).  The  into  fluvial,  intertidal,  lagoon,  marginal-supratidal,  and b a r r i e r  subsystems,  with  distinctive  d e p o s i t i o n a l e n v i r o n m e n t s and  one  or  more  characteristic system  has  l i t h o f a c i e s assemblages.  been e x a m i n e d  propagation  t r e a t e d as a fluvial  of  tide  and  The s t r u c t u r e  stochastic  sediment  through  process, the  dramatically  on an a n n u a l c y c l e .  the  short  former  and  reflecting  distribution, estuary.  associated  r u n by s e a s o n a l -  The  major  system and  seasonal  annual s a l i n i t y  may be of  are highly  system  change  responses a r e dominated i n  synoptic-scale  c i r c u l a t i o n process,  adjustments iand  input  cycle, with  60 p p t , e x h i b i t s a s h o r t  r e a c t i o n and long  to major  inputs  snowmelt r u n o f f  Although  transfers  system  Furthermore, the parameters of the  the  subsystems  perturbations.  non-linear.  Inputs  of  and surge w i t h i n t h e e s t u a r y  quasi-linear  water  associated  i n terms o f l i n k s between  and o v e r a l l s y s t e m r e s p o n s e t o i n p u t the  each  variance, in regime  the  t h e phase of  the  a range of a t l e a s t relaxation  response  i n May o r J u n e , when s a l t  water  is are  flushed completely effectively  year,  but  Although  unimportant,  of the e s t u a r y .  absent from the  play  direct  out  a  major  ice  effects  a d d i t i o n to r e s t r i c t i o n generation,  degradation  are  of  of  of  winter  m o n t h s of  the open-water by  ice  pervasive;  is  they  runoff  ground  ice,  open-water  season  and  and  in  wind  recession  surface  estuary  runoff.  e x c e e d 10"  surfaces.  lagoon  effects.  than the e s t i m a t e d the  fluvial  h a l f may At  be  climatic  time  In  a l m o s t an  the  sequence features,  development  of  also has  notably  aeolian, facies,  level,  the are  input.  by major  related  inputs  of m a g n i t u d e  to  the  greater  More t h a n 97%  of  approximately  system.  estuarine  l e v e l and  may  distinctive  delta,  i n J u n e ; of t h i s ,  scales,  fluctuations  marsh  order  transport  occur  sea  the  thermal  dominated  sediment  from the  distinctive  intertidal  wave  Water  are the  clastic  directly  rising  transgressive  ,  may  exported  by  - 1  littoral  input  long  dominated  kg a  in  suspended sediment s e r i e s d u r i n g  the  Fluvial  to  of  s y n o p t i c - s c a l e a n o m a l i e s of s e d i m e n t c o n c e n t r a t i o n storm  relatively  due  production  supratidal  volume, s a l i n i t y ,  synoptic-scale  to  season.  include,  and  the  f l o o d e v e n t s on d e l t a i c s u p r a t i d a l  coastal  t h e r m o k a r s t m o r p h o l o g y on  the  sediment  important  enhanced r a t e s  storage  during  8-9  c r e a t i o n o f h y p e r s a l i n e c o n d i t i o n s , c o n t r o l of  sedimentologically flats,  system d u r i n g  role  t r a n s p o r t of  W i n d - g e n e r a t e d waves  system  has  been  c o a s t a l r e c e s s i o n ; Holocene have  been  developed, the  important. including  absence  or  A  various limited  backbarrier-margin, tidal-delta,'and a  largely  afaunal  intertidal  iv  component,  and  and a b u n d a n t  deltaic  lake basins.  a sinuous  gravel  documented  type.  primarily  deposits The  channel The  basal  fluvial  assemblage  Babbage  of  Estuary  t r a n s g r e s s i v e , but i n c o r p o r a t e s  progradational  and i n l e t - m i g r a t i o n m o d e l s .  transgressive, progradational, occur  with poorly developed  i n close proximity  component a  includes  hitherto  barrier  levees  poorly  sequence i s  l o c a l i z e d e l e m e n t s of Examples  and i n l e t - f i l l  on t h e c e n t r a l Yukon  barrier coast.  of  major  sequences  V  TABLE OF CONTENTS  ABSTRACT  i i  L I S T OF TABLES  viii  L I S T OF FIGURES  x i i  ACKNOWLEDGEMENTS  xxx i i i  INTRODUCTION  1  1.1 P r e a m b l e 1.1.1 D e f i n i t i o n  1 of study  1  1.2 C o n c e p t u a l a p p r o a c h  4  1.2.1 G e o p h y s i c a l s y s t e m s  4  1.2.2 E n v i r o n m e n t s a n d f a c i e s  9  1.2.3 E s t u a r i n e s y s t e m s  11  1.3 The p r e s e n t s t u d y  17  1.3.1 Babbage e s t u a r i n e s y s t e m  17  REGIONAL CONTEXT: NORTHERN YUKON AND BEAUFORT SEA 2.1 G e o g r a p h y a n d p a l a e o g e o g r a p h y 2.1.1  Contemporary  26  geography  26  2.1.2 L a t e - Q u a t e r n a r y p a l a e o g e o g r a p h y 2.2 A t m o s p h e r i c e n v i r o n m e n t 2.2.1  Contemporary  2.2.2 L o w - f r e q u e n c y  45 of c l i m a t e  2.3 O c e a n o g r a p h i c e n v i r o n m e n t 2.3.1  38 45  climate variability  26  W a t e r a n d c i r c u l a t i o n i n M a c k e n z i e Bay  56 62 62  2.3.2 I c e i n t h e s o u t h e r n B e a u f o r t S e a  69  2.3.3  76  T i d e s and storm surges  2.3.4 Wave c l i m a t e  84  vi  HYDROLOGICAL SUBSYSTEM  94  3.1 F r e s h w a t e r i n p u t s t o t h e e s t u a r y 3.1.1 R u n o f f a n d p r e c i p i t a t i o n  inputs  3.2 M a r i n e i n p u t s t o t h e e s t u a r y 3.2.1 Water  l e v e l s a t t h e marine boundary  3.3 S y s t e m r e s p o n s e  94 94 118 118 144  3.3.1 T i d a l p r o p a g a t i o n w i t h i n t h e e s t u a r y  144  3.3.2 S u p r a t i d a l f l o o d i n g  155  3.3.3 I c e i n t h e e s t u a r y  170  3.3.4 P r o p e r t i e s o f w a t e r i n t h e e s t u a r y  185  3.3.5 The n o n - t i d a l c i r c u l a t i o n  207  3.3.6 Water  230  budget and s t r u c t u r e of t h e s y s t e m  SEDIMENTOLOGICAL SUBSYSTEM 4.1 F l u v i a l  sediment i n p u t s t o the estuary  4.1.1 S e d i m e n t 4.1.2 F l u v i a l  s o u r c e s and m a t e r i a l s transport processes  4.1.3 T o t a l f l u v i a l  sediment input  4.2 M a r i n e s e d i m e n t i n p u t s t o t h e e s t u a r y  243 243 243 252 289 296  4.2.1 S e d i m e n t  s o u r c e s and m a t e r i a l s  296  4.2.2 L i t t o r a l  transport processes  303  4.2.3 T o t a l m a r i n e s e d i m e n t i n p u t 4.3 S y s t e m r e s p o n s e  314 317  4.3.1 S e d i m e n t t r a n s f e r s w i t h i n t h e e s t u a r y  317  4.3.2 S e d i m e n t a t i o n a n d e r o s i o n  347  4.3.3 S e d i m e n t b u d g e t a n d s t r u c t u r e o f t h e s y s t e m  367  4.4 S e d i m e n t s t o r a g e component  376  4.4.1 G e n e r a l c h a r a c t e r i s t i c s  376  4.4.2 F l u v i a l  392  facies  vii  4.4.3 D e l t a p l a i n 4.4.4 D i s t r i b u t a r y  facies and i n t e r t i d a l  398 facies  414  4.4.5 L a g o o n , b a r r i e r , a n d m a r g i n a l f a c i e s  422  4.4.6 The t r a n s g r e s s i v e s e q u e n c e  435  CONCLUSIONS  *  447  REFERENCES  457  APPENDICES  495  OF  TABLES  S c a l e s of v a r i a n c e  Morphometry coast  Monthly  of  in Arctic  estuarine  systems  l a g o o n s and b a r r i e r s o f t h e Yukon  p r e c i p i t a t i o n d a t a , Kay P o i n t  Selected observations of s u r f a c e embayments of t h e c e n t r a l Yukon a d j a c e n t w a t e r s o f M a c k e n z i e Bay  salinity in coast and i n  Potential  f e t c h w i t h £3/10  i c e , Kay P o i n t , 1975  Potential  f e t c h w i t h <3/10  i c e , Kay P o i n t , 1976  Principal tidal constituents Kay P o i n t  Mean sea 1962-1975  Summary Babbage  level  at  Tuktoyaktuk  and  a n d summer a n o m a l y , T u k t o y a k t u k ,  statistics Estuary  for  catchments  draining  Estimates o f a n n u a l peak d i s c h a r g e , Babbage a t B I and Deep C r e e k a t D l , 1974-1977  to  River  M a j o r t i d a l c o n s t i t u e n t s a t Kay  P o i n t by  month 121  Summary o f d i s s o l v e d c o n s t i t u e n t s i n w a t e r s a m p l e s f r o m t h e Babbage E s t u a r y s y s t e m and P h i l l i p s Bay 189 S t r a t i f i c a t i o n and c i r c u l a t i o n p a r a m e t e r s f o r the Babbage E s t u a r y at s t a t i o n 12 d u r i n g s u c c e s s i v e t e n - d a y i n t e r v a l s i n t h e summer o f 1976. 210 Product-moment c o r r e l a t i o n c o e f f i c i e n t s f o r mean density, transverse s t r a t i f i c a t i o n , and v e r t i c a l stratification in Babbage Estuary entrance (stations 5-7) 223 C o m p a r i s o n o f w a t e r t r a n s f e r e s t i m a t e s f o r Babbage Estuary entrance section (Ml) as o b t a i n e d f r o m c u r r e n t m e t e r d a t a and by e q u a t i o n 3.3.6-1 233 W a t e r b u d g e t f o r Babbage E s t u a r y , J u n e - A u g u s t 1976  J a n u a r y 1976  and 240  Summary of d i s s o l v e d c o n s t i t u e n t s i n w a t e r s a m p l e s f r o m t h e Babbage R i v e r and Deep C r e e k drainage ba s i n s 248 Petrographic analyses of s a n d and Babbage R i v e r c h a n n e l b e t w e e n T u l u g a q c o n f l u e n c e and s e c t i o n B l  g r a v e l from (Crow) R i v e r 250  Sediment t r a n s p o r t Crow R i v e r  summary,  Babbage  River  below 290  Sediment transport Babbage distributary  summary,  Deep  Creek  above 291  Distribution Babbage R i v e r  of and  sediment transport Deep Creek  by  type, 294  Summary of net wave-generated longshore sediment transport f o r p r o x i m a l and d i s t a l Kay Point spit and N i a k o l i k foreshore, 1975-1976 315  S t a t i s t i c s of S e c c h i e x t i n c t i o n in the Babbage E s t u a r y , 1976  depth  for  stations 341  Flushing  times  for  the  Babbage  Estuary 343  Thickness of on vegetated 8 June 1976  f r e s h l y d e p o s i t e d sediment at sites supratidal f l a t s , Babbage Delta, 349  Erosion and s e d i m e n t a t i o n on i n t e r t i d a l of the Babbage D e l t a , summer 1976  surfaces 355  Sediment Babbage 1976  accumulation rates in traps deployed in Lagoon and i n l a k e s of the Babbage Delta, 358  A n a l y s i s of v a r i a n c e to determine s i g n i f i c a n c e of differences in sediment t r a p data between sites, Babbage E s t u a r y , 1976 359  Approximate system,  sediment  January,June,  budget July,  for and  Babbage August,  Estuary 1976 369  XI  30  L i t h o f a c i e s types Babbage Estuary  of  lower  Babbage  River  and 379  31  Benthic i n v e r t e b r a t e s i n Ekman dredge samples from the Babbage Estuary near s t a t i o n 7a, 24 J u l y 1975 425  32  A: Delaware surficial transgressive sequence (adapted from K r a f t , 1971); B: Babbage Lagoon s u r f i c i a l t r a n s g r e s s i v e sequence 437  33  Babbage D e l t a  surficial  transgressive  sequence 444  xi i  L I S T OF  FIGURES  Map of the Yukon coast, showing Babbage Estuary system and other f e a t u r e s , i n c l u d i n g m a j o r l a g o o n s and  location of topographic estuaries 2  2  Map o f t h e B a b b a g e E s t u a r y s y s t e m , showing major sampling stations, locations of t i d e and stage recorders, hydrometric s e c t i o n s , and location of m e t e o r o l o g i c a l s t a t i o n a t Kay Point  3  B a t h y m e t r y of Babbage E s t u a r y i n 1975; v i e w a c r o s s main e n t r a n c e s e c t i o n t o w a r d Kay P o i n t s p i t , w i t h Babbage L a g o o n t o r i g h t , Kay Point in distance, and N i a k o l i k P o i n t i n foreground  4  A: view of the Babbage D e l t a , showing i n t e r t i d a l a n d s u p r a t i d a l s u r f a c e s ; B: l o w e r Babbage River, l o o k i n g downstream t o w a r d s e c t i o n BI 21  5  Babbage Delta and southern lagoon, showing coordinate system, intertidal transects, sites w h e r e t h e t h i c k n e s s o f f r e s h s e d i m e n t was m e a s u r e d on the delta p l a i n a n d on i c e , a n d l o c a t i o n s o f sediment t r a p s , excluding s i t e s in the northern lagoon  Babbage Estuary system, showing b o r e h o l e l o c a t i o n s and l o c a t i o n s of exposures  grid short  network, cores or 24  7  W e s t e r n p a r t of Yukon C o a s t a l P l a i n with British Mountains in b a c k g r o u n d ; A: B a c k h o u s e L a g o o n ; B: F i r t h R i v e r fan w i t h Nunaluk Lagoon i n foreground  XI 1 1  A: headwaters of Babbage River with Tertiary p e d i m e n t a n d i c i n g , 29 A u g u s t 1 9 7 6 ; B: upper Trail River basin in B r i t i s h Mountains near Mount Sedgewick 28  9  Massive between coast  ground ice in Kay P o i n t and  ice-thrust sediments exposed King Point, Mackenzie Bay 30  10  Barriers and lagoons King Point (B), central  at Stokes Point Yukon coast  (A)  and  at 33  11  Hypsometric curves for Creek drainage basins  Babbage  River  and  Deep  36 12  Tentative palaeogeography Island  late-Wisconsinan between Kay Point  and and  1826 Herschel 39  13  Profile a l o n g a x i s of Babbage V a l l e y and H e r s c h e l Basin, showing hypothesized late-Wisconsinan water l e v e l in Lake Herschel and present, valley-axis s l o p e s of Babbage R i v e r and tributaries  42 14  Data base and tentative history of late W i s c o n s i n a n and Holocene sea l e v e l s in Mackenzie D e l t a a n d on t h e Y u k o n c o a s t (after Forbes, 1980) 44  15  Monthly Komakuk and for  temperature and precipitation data for B e a c h and S h i n g l e P o i n t on the Yukon c o a s t O l d Crow (south of the mountains) 46  16  Cumulative precipitation northern Yukon T e r r i t o r y ,  at stations summer 1974  in  the 51  XIV  17  Variance pressure  density spectrum of hourly atmospheric a t Kay P o i n t , summer 1976 52  18  R e l a t i v e f r e q u e n c i e s o f h o u r l y w i n d s p e e d (m/s) by direction, 1975 a n d 1976 summer records, Kay Point. 53  19  Variance density^ spectra f o r n o r t h e a s t e r l y and n o r t h w e s t e r l y components of h o u r l y wind stress., Kay P o i n t , 1976 55  20  Representative temperature i n M a c k e n z i e Bay  and s a l i n i t y  profiles 64  21  L a n d s a t image 1 - 1 4 2 2 - 2 0 1 8 5 - 5 , 18 September 1973, showing M a c k e n z i e R i v e r plume s p r e a d i n g n o r t h a n d e a s t , w i t h an a b r u p t w e s t e r n b o u n d a r y i n M a c k e n z i e Bay 66  22  Portion of Landsat image 1-1460-20292-6, 26 O c t o b e r 1 9 7 3 , s h o w i n g open w a t e r i n M a c k e n z i e Bay a n d t h i n i c e i n H e r s c h e l Basin, in Phillips Bay, west o f H e r s c h e l I s l a n d , a n d i n a l l l a g o o n s 71  23  Portion of Landsat image 1-1317-20374-6, 5 J u n e 1 9 7 3 , s h o w i n g n a r r o w band o f l a n d f a s t i c e west o f Herschel Island, extensive landfast ice in Mackenzie_Bay, and l e a d i n t h e shear-zone between l a n d f a s t i c e and s e a s o n a l pack 71  24  Frequency distribution l e v e l s at Tuktoyaktuk  of  extreme monthly  water 81  P l o t s of estimated versus h e i g h t , Kay P o i n t s p i t  o b s e r v e d wave p e r i o d and •  88  R e f r a c t i o n o f waves a t T=4.2s a p p r o a c h i n g f r o m t h e NNW a n d o f waves a t T=4.9s a p p r o a c h i n g from the east; sites f o r w h i c h h i n d c a s t c o m p u t a t i o n s and longshore sediment transport estimates were obtained are also p l o t t e d 90 Frequency distributions of t a n g e n t i a l and normal c o m p o n e n t s o f wave power a t t h e d i s t a l end o f Kay P o i n t s p i t , b a s e d on h i n d c a s t wave a n a l y s i s 93 Daily runoff (Babbage R i v e r a t B l ) and d a i l y p r e c i p i t a t i o n a t Kay Point and S h i n g l e Point, 1974-1976 97 Cumulative precipitation at Shingle Point c u m u l a t i v e r u n o f f i n Babbage R i v e r ( B l ) a n d C r e e k ( D I ) , 1975 a n d 1976  and Deep 101  Time o f d i u r n a l peak f l o w d u r i n g summer i n Babbage R i v e r a t B l , 1975 and 1976  recession 106  Babbage R i v e r d i s c h a r g e , 2 J u l y 1976  section  B l , 21 J u n e  to 108  Storm hydrographs, Babbage River, showing non-exponential c h a r a c t e r of  August 1976, recessions 110  Frequency distributions of d a i l y runoff for s n o w m e l t and summer seasons 1 9 7 4 - 1 9 7 6 , Babbage River at B l 113  xvi  34  Variance d e n s i t y s p e c t r a of h o u r l y discharge: Babbage R i v e r a t B I , summer 1975; Deep Creek a t D l , summer 1976 115  35  H o u r l y water l e v e l a t marine boundary Estuary: summer 1974, summer breakup+summer 1976  of Babbage 1975, and 119  36  V a r i a n c e d e n s i t y spectrum of h o u r l y water l e v e l a t Kay P o i n t s p i t (gauge A, CHS s t a t i o n 6515), 12 J u l y t o 12 September 1975 120  37  Cumulative normalized variance spectra f o r hourly water l e v e l a t marine boundary, Babbage E s t u a r y 124  38  Variance density spectrum of hourly water temperature a t s t a t i o n 5, Babbage E s t u a r y , d u r i n g 20 days of r e c o r d i n August 1975 128  39  Wind, a t m o s p h e r i c p r e s s u r e , and water l e v e l a t Kay Point during 1975, illustrating phase correspondence between low-pass water l e v e l and n o r t h w e s t e r l y wind speed but v a r i a b l e a m p l i t u d e of surge response 131  40  Wind, a t m o s p h e r i c p r e s s u r e , and water l e v e l a t Kay Point during 1976, illustrating phase correspondence between low-pass water l e v e l and n o r t h w e s t e r l y wind speed 132  41  P a r t i a l coherence between n o r t h w e s t e r l y wind s t r e s s  water  level  and 135  xvi i  42  Frequency distributions of daily-maximum hourly water l e v e l f o r t h e l a t e June t o e a r l y September season i n three d i f f e r e n t y e a r s , Kay P o i n t s p i t data 138  43  H i g h - f r e q u e n c y and t r a n s i e n t response of water level t o wind a s s o c i a t e d w i t h c o l d - f r o n t passage, 30 J u l y 1976 140  44  Minor surge with abrupt shock high-frequency low-amplitude variance on Niakolik Point (gauge-B) t i d a l 6 A u g u s t 1976  front and superimposed record for 141  45  W a t e r l e v e l s a t g a u g e s A and E, 19-25  August  1975 146  46  Water l e v e l sequence a t D e l t a , l a t e J u l y 1976  gauge C,  distal  Babbage 146  47  P a r t i a l c o h e r e n c e : (A) b e t w e e n gauge-A and gauge-E water levels; (B) b e t w e e n B l and gauge-E w a t e r levels 148  48  Comparison between variance density spectra of ?E'(t) and of 5 ( t ) , showing c l o s e agreement a t f<10" c h" E  1  1  151 49  50  Gain function f o r t i d a l system  Lag function t i d a l system  for  Babbage  Estuary  cooscillating 152  Babbage  Estuary  cooscillating 154  xvi i i  51  Complete duration sequences f o r hourly level, Babbage E s t u a r y marine boundary, 1975 a n d s p r i n g - s u m m e r 1976  water summer 156  52  Driftwood deposits transgressive limit gauge E i n t h e v a l l e y  marking near Kay  the Point  present and near 158  53  D i s t r i b u t i o n of major d r i f t w o o d deposits i n the Babbage Estuary system, 22 A u g u s t 1944 a n d 20 A u g u s t 1970 159  54  Record of storm-surge event, l e v e l s a t gauges A and E  27 A u g u s t  1975: water 162  55  Water l e v e l a t Niakolik Point (gauge B) a s a f u n c t i o n o f Babbage R i v e r d i s c h a r g e , s p r i n g a n d summer 1976 164  56  Babbage R i v e r d i s c h a r g e , gauge-B w a t e r l e v e l , and bottomfast i c e t h i c k n e s s a t a s i t e i n t h e Babbage E s t u a r y n e a r gauge B, 1-30 J u n e 1976 166  57  Supratidal flooding of Babbage Delta with b o t t o m f a s t i c e i n t h e l a g o o n , 9 t h and 1 0 t h of June 1974 167  58  59  Schematic plot of monthly i c ethickness (after S c h e l l , 1974) a n d p r o p o r t i o n s o f e s t u a r i n e s t o r a g e volume i n s o l i d and l i q u i d phases  Ice i n the northern Babbage L a g o o n and p r o x i m a l Babbage D e l t a , l a t e May 1974  171  i n the 17.2  xix  60  Chronology 1974-1976  of  breakup  in  the  Babbage E s t u a r y , 177  61  A: S p r i n g R i v e r , s h o w i n g s n o w m e l t r u n o f f c o n t a i n e d and d e f l e c t e d by the Spring River barrier; overflow of Babbage R i v e r w a t e r o n t o i c e o u t s i d e Babbage E s t u a r y is visible i n the background, 30 May 1974; B: i c e f l o a t i n g i n main d i s t r i b u t a r y c h a n n e l o f Babbage E s t u a r y between d i s t a l delta and N i a k o l i k P o i n t , 9 J u n e 1974 178  62  Drainage holes through i c e o u t s i d e main e n t r a n c e section and general view of central lagoon, showing limited extent o f f l o o d i n g o v e r - i c e and open w a t e r i n e n t r a n c e c h a n n e l 30 May 1974 182  63  S c h e m a t i c p l o t of monthly water temperature salinity i n the Babbage E s t u a r y , b a s e d on o b s e r v a t i o n s f o r t h e summer months and 1974 ( a f t e r S t e i g e n b e r g e r e t a l . , 1975) f o r A p r i l , other values interpolated  and 1976 data with 191  64  Daily sequence of water t e m p e r a t u r e , s, density, p, and viscosity, n, E s t u a r y e n t r a n c e , J u n e - S e p t e m b e r 1976  , salinity, in Babbage 194  65  Daily s e q u e n c e of w a t e r t e m p e r a t u r e , 9 , s a l i n i t y , s, d e n s i t y , P , and v i s c o s i t y , n, a t s t a t i o n 12, Babbage D e l t a , J u n e - S e p t e m b e r 1976 195  66  Daily temperature, salinity, density, and v i s c o s i t y i n Babbage E s t u a r y , 24 J u l y t o 5 August 1977 197  67  Estimates of the variance of water d e n s i t y f o r s e t s of d a t a a t v a r i o u s s a m p l i n g i n t e r v a l s , t A  199  XX  68  69  Time s e q u e n c e i n c l u d i n g t h e s t o r m s u r g e event of 27 A u g u s t 1975: 12h maximum, minimum, and instantaneous a i r temperature; h a l f - h o u r l y water temperature; wind speed and direction at Kay P o i n t ; w a t e r l e v e l a t gauge A; and Babbage River d i s c h a r g e a t BI  202  S u r f a c e s a l i n i t y i n t h e Babbage E s t u a r y f o l l o w i n g t h e s t o r m o f 27 A u g u s t 1975 204  70  Examples of salinity stratification in main distributary c h a n n e l and entrance section of Babbage E s t u a r y , 1 S e p t e m b e r 1976 and 31 J u l y 1975 213  71  Change i n p a t t e r n o f salinity stratification in main d i s t r i b u t a r y a n d e n t r a n c e s e c t i o n o f Babbage E s t u a r y o v e r a 3-4h p e r i o d o f ebb flow, 30 J u l y 1975 214  72  Changes i n the p a t t e r n of s a l i n i t y stratification o v e r n i n e - h o u r i n t e r v a l , 31 J u l y t o 1 A u g u s t 1975 215  73  Surface Babbage 1976  velocity Estuary,  distribution i n Ml section, d u r i n g ebb 1 4 2 3 - 1 6 0 3 h 10 A u g u s t 218  74  S u r f a c e and n e a r - b o t t o m v e l o c i t i e s i n M l section, Babbage E s t u a r y e n t r a n c e , d u r i n g f l o o d 1 2 0 0 - 1 3 3 0 h 3 A u g u s t 1976, s h o w i n g c o n t i n u e d ebb f l o w at a l l depths over the c e n t r a l s h o a l , w i t h water e n t e r i n g a t d e p t h v i a c h a n n e l s n e a r s t a t i o n s 5 and 7 220  75  Time sequence of s u r f a c e and b o t t o m s a l i n i t y a t s t a t i o n s 2, 5, and 7 i n Babbage E s t u a r y , o f gauge-A water level, and of wind speed and direction a t Kay Point, showing response of vertical salinity distributions to wind-induced mixing; wave h e i g h t s a r e superimposed on the salinity sequence 221  xxi  76  L o n g i t u d i n a l and t r a n s v e r s e components of v e l o c i t y at s t a t i o n 5, l o w - p a s s and h i g h - p a s s filtered components, and water l e v e l a t gauge A, Babbage E s t u a r y , 12-31 A u g u s t 1975 225  77  Capacity of water l e v e l  t h e Babbage E s t u a r y a s a f u n c t i o n o f 231  78  Net exchange flow through Ml section, gauge-B water level, a n d Babbage R i v e r d i s c h a r g e t h r o u g h B I s e c t i o n , J u n e 1976 234  79  H o u r l y s t o r a g e volume d u r i n g summer 1975  in  the  Babbage  Estuary 235  80  81  V a r i a n c e d e n s i t y spectrum of h o u r l y s t o r a g e volume i n t h e Babbage E s t u a r y d u r i n g summer 1975  237  P a r t i a l c o h e r e n c e b e t w e e n Babbage R i v e r d i s c h a r g e , Qf(t), and M l n e t o u t p u t sequence, Q n ( t ) , showing extreme n o n - l i n e a r i t y of r u n o f f t r a n s f e r s through the estuary, particularly in the synoptic f r e q u e n c y band i n w h i c h most o f t h e v a r i a n c e o f runoff resides 238  82  S i m p l i f i e d c a n o n i c a l s t r u c t u r e of the h y d r o l o g i c a l s u b s y s t e m d u r i n g l a t e - w i n t e r , s n o w m e l t , a n d summer seasons, showing d r a m a t i c c h a n g e s i n t h e number and c h a r a c t e r o f i n t e r n a l a n d e x t e r n a l l i n k s 242  83  I n c i s e d m i d d l e c o u r s e o f Babbage R i v e r : (A) m a j o r exposure of Cretaceous or e a r l i e r sediments a d j a c e n t t o t h e c h a n n e l ; (B) T e r t i a r y g r a v e l over o l d e r sediments i n a spur above t h e r i v e r 244  A: steep braided channels d r a i n i n g unvegetated r i d g e s i n Barn M o u n t a i n s , e a s t e r n p a r t of Babbage R i v e r b a s i n , A u g u s t 1 9 7 6 ; B: b l o c k s l u m p i n g due t o thermo-erosional n i c h e d e v e l o p m e n t , l o w e r Babbage R i v e r , l a t e J u l y 1976 245 Representative particle-size distributions for source materials and f o r s e d i m e n t s s t o r e d i n t h e c h a n n e l s y s t e m , Babbage R i v e r b a s i n 250 A: incombustible suspended sediment and total dissolved s o l i d s c o n c e n t r a t i o n s (mg/L) i n Babbage R i v e r a t B l , 1 9 7 5 ; B: incombustible suspended sediment and t o t a l dissolved solids transport (kg/s) 254 A: t o t a l s u s p e n d e d s e d i m e n t and t o t a l dissolved solids concentrations (mg/L) i n Babbage R i v e r a t B l , 1976; B: t o t a l s u s p e n d e d a n d t o t a l dissolved s o l i d s transport (kg/s) 255 A: total suspended sediment and t o t a l d i s s o l v e d s o l i d s c o n c e n t r a t i o n s (mg/L) i n Deep C r e e k a t D I , 1976; B: total suspended and t o t a l dissolved s o l i d s t r a n s p o r t (kg/s) 256 D i s s o l v e d , suspended, and b e d l o a d r a t i n g s , R i v e r a t B l , 1976  Babbage 258  D i s s o l v e d , suspended, C r e e k a t D I , 1976  and  bedload  ratings,  Deep 259  T o t a l d i s s o l v e d s o l i d s c o n c e n t r a t i o n as a f u n c t i o n of d i s c h a r g e , Babbage R i v e r a t B l , 1976 262  Total dissolved solids concentration of d i s c h a r g e D e e p C r e e k a t D I , 1976  as a  function 263  Water discharge and total dissolved solids concentration (estimated "from specific conductivity corrected for 0 ), showing two transients of high TDS concentration during . b r e a k u p and s n o w m e l t f l o o d o f J u n e 1975, Babbage River W  266 Phase r e l a t i o n s between incombustible suspended sediment concentration (mg/L) and discharge ( m s ) , Babbage R i v e r a t B l , 1975 and 1976 3  _ 1  Phase r e l a t i o n s between incombustible suspended sediment concentration (mg/L) and discharge ( m s ) , Deep C r e e k a t D I , 1975 and 1976, showing h y s t e r e s i s d u r i n g a n n u a l snowmelt f l o o d s 3  269  - 1  Hysteresis in suspended-sediment/discharge r e l a t i o n during Babbage R i v e r f l o o d of 8 June 1974, showing peaks i n TSS c o n c e n t r a t i o n both b e f o r e and a f t e r peak s t a g e and counter-clockwise h y s t e r e s i s l o o p f o r t h e f l o o d as a w h o l e  270  272  Sample d a t a and t h e o r e t i c a l r a t i n g s for bedload t r a n s p o r t , Babbage R i v e r a t B l , 1976 277 P a r t i c l e - s i z e d i s t r i b u t i o n s f o r v a r i o u s samples of s e d i m e n t i n c h a n n e l d e p o s i t s o r m o v i n g as b e d l o a d , Babbage R i v e r a t B l 281 Three s e t s of e m p i r i c a l r e s u l t s f o r the hiding f a c t o r ^ as a f u n c t i o n of D / D i n rough t u r b u l e n t flow 5Q  282  C h a n n e l b e d p r o f i l e s a t s e c t i o n B I (Babbage R i v e r ) between 28 May and 8 June 1975, showing d e g r a d a t i o n of b o t t o m f a s t i c e 286 Channel bed p r o f i l e s at section BI (Babbage R i v e r ) ; A, 1 9 7 5 : s c o u r d u r i n g rising l i m b of a n n u a l snowmelt h y d r o g r a p h , s h o w i n g d e v e l o p m e n t o f scour-hole against bank i n t h a l w e g ; B, 1 9 7 6 : p r o f i l e s s h o r t l y a f t e r peak flow on 6 J u n e and 26 J u n e , net f i l l 10-15 J u n e , and n e t s c o u r 15-19 J u n e 288 C u m u l a t i v e p e r c e n t of t o t a l sediment t r a n s p o r t Babbage R i v e r a t B I i n 1975 a n d 1976  in 293  A: c o a s t a l segment 1 near Kay P o i n t , s h o w i n g undercutting and f a i l u r e of polygonal blocks formed by i c e - w e d g e thaw o r f r a c t u r e , J u l y 1 9 7 6 ; B: c o a s t a l segment 2, s h o w i n g major impact of retrogressive-thaw and associated mudflow transport of f i n e sediment a c r o s s the beach, A u g u s t 1977 298 Turbid Mackenzie River water o f f c e n t r a l Yukon c o a s t ; A: p a r t o f L a n d s a t image 1-1089-20020-5, 17 J u l y 1975, showing advection of suspended s e d i m e n t p a s t Kay P o i n t ; B: l e a d i n g edge o f M a c k e n z i e R i v e r plume o f f Kay P o i n t , 28 J u l y 1976 301 Vertical photograph o f Kay P o i n t a n d Babbage E s t u a r y , showing l o n g s h o r e t r a n s p o r t of suspended sediment westward past Kay P o i n t and wide s h o r e - n o r m a l d i s p e r s i o n i n P h i l l i p s Bay; p a r t of NAPL p h o t o g r a p h A 2 2 9 7 5 - 5 6 , 4 A u g u s t 1972 304 Daily l o n g s h o r e sediment t r a n s p o r t a t d i s t a l end of Kay P o i n t spit, positive toward t h e main e n t r a n c e s e c t i o n ( M l ) , c o m p u t e d f r o m h i n d c a s t wave d a t a u s i n g e q u a t i o n 4.2.2-6 310  Proximal end o f Kay P o i n t s p i t , s h o w i n g t e m p o r a r y (M3) i n l e t ; part o f NAPL p h o t o g r a p h A21830-2, 18 A u g u s t 1970 312 Viscosity, S t o k e s s e t t l i n g v e l o c i t y f o r D=l ym, and total suspended solids concentration at s t a t i o n 7, Babbage E s t u a r y , 1976 319 Scanning e l e c t r o n m i c r o g r a p h s of sediment from t h e Babbage E s t u a r y ( s i t e 021125), showing s i l t - and c l a y - s i z e m i n e r a l p a r t i c l e s and v a r i o u s composite p a r t i c l e s of s i l t s i z e 322 Scanning e l e c t r o n m i c r o g r a p h s of sediment from t h e Babbage Estuary ( s i t e 010140), showing both p e l l e t i z e d and a n g u l a r forms of a g g l o m e r a t i o n 323 Particle-size distributions f o r bottom sediment and f o r suspended sediment c o l l e c t e d i n t r a p s a t s i t e 010140, Babbage L a g o o n , showing effects of various treatments 325 Longitudinal thalweg profiles in t h e main d i s t r i b u t a r y c h a n n e l o f t h e Babbage D e l t a , s h o w i n g (A) p r e d o m i n a n c e o f e b b - d i r e c t e d t r a n s p o r t a n d (B) rare occurrence of flood-directed bedforms d o w n s t r e a m f r o m s t a t i o n 10 329 Horizontal reflectors Deep C r e e k channel, fluid-mud  i n c r o s s - s e c t i o n s of lower suggesting presence of 331  Time sequence of total suspended solids c o n c e n t r a t i o n a t s t a t i o n 1 2 , Babbage D e l t a , with wind s p e e d a n d d i r e c t i o n a t Kay P o i n t a n d Babbage R i v e r d i s c h a r g e , s p r i n g a n d summer 1976 333  xxvi  115  Distribution o f C ( 0 ) i n t h e Babbage Estuary during t h e s t o r m - s u r g e o f 27 A u g u s t 1975 (A) a n d on 14 A u g u s t 1976 ( B ) , when a plume of turbid water f i l l e d P h i l l i p s Bay a s f a r n o r t h e a s t a s Kay Point T  337 116  W a t e r l e v e l and l o n g i t u d i n a l v e l o c i t y ( s t a t i o n 5; h-z=0.9 m), s e c o n d h a l f o f A u g u s t 1 9 7 5 ; u p p e r m o s t record i s time sequence current speed, showing distribution of v a l u e s e x c e e d i n g an a p p r o x i m a t e e n t r a i n m e n t t h r e s h o l d o f 0.15 m/s 338  117  Estimated concentration of total suspended sediment, based on h o u r l y S e c c h i e x t i n c t i o n d a t a a t s t a t i o n s 5, 6, a n d 7 i n t h e e n t r a n c e section and s t a t i o n 12 i n t h e d e l t a d u r i n g a 4 8 - h p e r i o d i n J u l y 1976 340  118  Ice r a f t i n g of sediment p l a i n , J u n e 1976  onto  supratidal  delta 346  119  Ice i n Babbage D e l t a l a k e s a f t e r s p r i n g showing b a s i n s w i t h and w i t h o u t sediment (A) 15 J u n e 1974; (B) 18 J u n e 1976  flooding, on i c e ; 351  120  Sediment on i c e , f o r m e r l y bottomfast; (A) i n l a g o o n near t h e d i s t a l end of t h e s p i t (015080), apparently rafted from a location closer to the d e l t a ; a n d (B) i n P h i l l i p s Bay n e a r section Ml ( s i t e 000050) 353  121  Sediment trap locations and d i s t r i b u t i o n of accumulation rates (kg m " d a y ) f o r the i n t e r v a l 24 J u n e t o 16 J u l y i n 1976 2  _ 1  357  Rates of sediment a c c u m u l a t i o n (kg m d a y " ) i n t r a p s d e p l o y e d a t l a g o o n - and l a k e - b o t t o m s i t e s i n t h e Babbage E s t u a r y s y s t e m , J u n e - S e p t e m b e r 1976 _ 2  1  360 Distribution of sediment accumulation (kg m " d a y ) i n traps i n t h e Babbage E s t u a r y , 8/9-14/15 A u g u s t 1976 2  _ 1  362 A r e a o f s u p r a t i d a l f l a t l o s t t o bank e r o s i o n a l o n g w e s t e r n a n d main distributary channels of the Babbage Delta, August 1944 t o A u g u s t 1 9 7 0 , d e t e r m i n e d from a i r p h o t o g r a p h s ; e x t e n t of e r o s i o n i n d i c a t e d by s h a d i n g 365 D e g r a d a t i o n of v e g e t a t e d s u p r a t i d a l Babbage D e l t a , A u g u s t 1975  flats,  distal 366  Total suspended sediment c o n c e n t r a t i o n a t s e c t i o n B l , Babbage R i v e r , a n d e s t i m a t e d t o t a l suspended s e d i m e n t c o n c e n t r a t i o n , b a s e d on S e c c h i e x t i n c t i o n depth, a t s t a t i o n s 5, 6, 7, a n d 7a i n t h e e s t u a r y d u r i n g J u n e 1976 371 P a r t o f NAPL p h o t o g r a p h A 1 3 3 8 3 - 1 5 1 , 1 9 5 2 , s h o w i n g configuration of d i s t r i b u t a r y c h a n n e l s seaward of the d i s t a l d e l t a margin very d i f f e r e n t from t h e 1972 m o r p h o l o g y ( c f . F i g u r e 105) 373 Canonical structure o f t h e s e d i m e n t a r y component o f t h e Babbage E s t u a r y s y s t e m , showing seasonal changes i n the l i n k a g e network 374 Map o f Babbage E s t u a r y s y s t e m s h o w i n g d i s t r i b u t i o n of major depositional environments and representative l i t h o f a c i e s types 378  xxvi i i  130  Sediment sampling locations in the Babbage Estuary, classified according to depositional e n v i ronment 381  131  T e r n a r y diagrams showing p r o p o r t i o n s of sand plus gravel, s i l t , and c l a y , f o r v a r i o u s components of t h e Babbage E s t u a r y s y s t e m 382  132  Ternary diagram sand, a n d mud and E s t u a r y  showing proportions of g r a v e l , i n s e d i m e n t s o f t h e Babbage R i v e r 386  133  R e l a t i o n between g r a p h i c s t a n d a r d d e v i a t i o n s graphic mean D f o r s u r f a c e sediments of Babbage D e l t a a n d E s t u a r y  and the 388  134  Borehole  d a t a , Babbage E s t u a r y  and D e l t a 390  135  D i s t r i b u t i o n of Holocene channel d e p o s i t s i n the lower valley, as interpreted from surface morphology and l i m i t e d exposures, showing major impact of Tulugaq r i v e r f a n on s e d i m e n t a t i o n i n t h i s p a r t of the v a l l e y 393  136  Lower Babbage R i v e r between T r a i l River and f u r t h e s t - s e a w a r d g r a v e l r i f f l e , i n 1954 ( l e f t ) a n d 1976 ( r i g h t ) ; p a r t s o f NAPL p h o t o g r a p h s A14406-48 and A24502-170 394  137  D i s t r i b u t i o n of l i t h o f a c i e s types a t the s u r f a c e , Babbage R i v e r a n d d i s t r i b u t a r y c h a n n e l immediately downstream from section BI; part o f NAPL p h o t o g r a p h A 2 1 8 2 6 - 8 7 , A u g u s t 1970 395  xxix  138  A i r and g r o u n d v i e w s of Babbage D e l t a , showing distributary, lacustrine, and supratidal components of the sediment system 399  139  T o p o g r a p h i c p r o f i l e o f c e n t r a l Babbage D e l t a a l o n g g r i d l i n e yyy=040 ( s e e F i g u r e 5 ) ; proximal delta at left, distal margin w i t h anomalous e l e v a t e d surface at r i g h t 400  140  Frequency distributions of surface area for v a r i o u s s u b s e t s of t h e pond and l a k e p o p u l a t i o n on the Babbage D e l t a ; a l s o p l o t t e d a r e d i s t r i b u t i o n s f o r an a r e a of l a g o o n - m a r g i n s u p r a t i d a l f l a t s , f o r anomalous surface with rugged microrelief on d i s t a l d e l t a , and f o r a r e p r e s e n t a t i v e a r e a i n t h e lower v a l l e y 402  141  Long profile o f t i d a l c h a n n e l and c r o s s - p r o f i l e s o f t h r e e l a k e s i n t h e c e n t r a l Babbage D e l t a 403  142  L e v e e s i n t h e Babbage D e l t a ; A: prominent levee beside minor d i s t r i b u t a r y c h a n n e l , northern d i s t a l margin of delta plain; B: bank w i t h n e g l i g i b l e l e v e e d e v e l o p m e n t , more t y p i c a l of the distal delta, right bank of main d i s t r i b u t a r y c h a n n e l b e t w e e n s t a t i o n s 10 and 12 405  143  Proximal delta plain; (A) showing vegetated s u p r a t i d a l left and flood-splay unit a b a n d o n n e d Babbage R i v e r distance; (B) sparsely flood-splay surface  looking upvalley, surface with lakes at at bottom r i g h t ; note channel in middle vegetated supratidal 406  144  F l o o d - s p l a y s e d i m e n t a t i o n s u r f a c e a d j a c e n t t o main d i s t r i b u t a r y c h a n n e l , c e n t r a l Babbage D e l t a ; part of NAPL p h o t o g r a p h A 2 1 8 2 6 - 8 1 , A u g u s t 1970 407  XXX  145  A: s p r u c e l o g s ( d r i f t w o o d ) i n s u p r a t i d a l s e d i m e n t s of t h e Babbage D e l t a ; B: s t r a t i f i e d o r g a n i c s i l t s o f t h e s u p r a t i d a l d e l t a p l a i n , p a r t o f s e c t i o n 405 in the c e n t r a l d e l t a 409  146  Anomalous r a i s e d s u r f a c e of rugged m i c r o r e l i e f a t d i s t a l m a r g i n o f c e n t r a l d e l t a p l a i n , J u n e 1976 411  147  Marginal supratidal flats o f Babbage Delta, showing thermokarst morphology a r i s i n g i n p a r t , a t l e a s t , from d e g r a d a t i o n of ice-wedge polygon nets 412  148  A: 7-kHz r e c o r d f r o m m a i n distributary channel, proximal d e l t a ; B: i n t e r p r e t a t i o n o f 7-kHz r e c o r d from main distribuary, distal delta near s t a t i o n 10 415  149  A: f l o o d - d i r e c t e d dune- and r i p p l e - s c a l e bedforms on d i s t r i b u t a r y - m a r g i n surface near t r a n s e c t 4, proximal Babbage D e l t a ; B: i c e - r a f t e d g r a v e l on distributary-margin i n t e r t i d a l - surface, central delta 416  150  Channel-margin and lagoon-margin intertidal s u r f a c e s i n t h e Babbage D e l t a , A u g u s t 1974 418  151  A: intertidal flats near t r a n s e c t 8, distal Babbage D e l t a , s h o w i n g t i d a l c h a n n e l n e t w o r k , w i t h patches o f c o l o n i z i n g P u c c i n e l l i a on l e v e e s , a n d e r o s i o n o f s u p r a t i d a l s u r f a c e , S e p t e m b e r 1 9 7 6 ; B: dessication cracks, associated small-scale scour, and d r a i n a g e v e n t s on l o w i n t e r t i d a l s u r f a c e . 419  152  Core s e c t i o n s from high intertidal shallow basin, distal delta plain F i g u r e 6)  surface i n (site 406, 420  P r o f i l e of Ml E s t u a r y marine  (main e n t r a n c e ) boundary  section,  Babbage 423  Gravel f o r m i n g low intertidal Lagoon (site 032080), showing a t t r i b u t e d to i c e scour  s h o a l i n Babbage linear grooves 425  A: Kay P o i n t b a r r i e r , w i t h P h i l l i p s Bay a t r i g h t and Babbage Lagoon a t l e f t , s h o w i n g w i d e b a c k s h o r e s u r f a c e l a r g e l y s n o w - f r e e , May 1976; B: Shingle Point spit, showing extensive and complex backbarrier deposits 427 A: Distal Kay Point spit, 27 August 1975, following a s e v e r e s t o r m and moderate surge, showing limited extent of washover deposits, a e o l i a n s a n d a c c u m u l a t i o n n e a r l a r g e l o g s on berm, and i c e i n c o r p o r a t e d i n f o r e s h o r e s e d i m e n t s ; (B) distal end of spit, 2 August 1974, showing subtidal backbarrier platform and post-1972 e x t e n s i o n of the s p i t 428 S c h e m a t i c s e c t i o n t h r o u g h Kay P o i n t s p i t , d i s t r i b u t i o n of upper b a r r i e r l i t h o f a c i e s  showing 429  A: l a g o o n - m a r g i n s u p r a t i d a l f l a t s a t n o r t h end o f Babbage L a g o o n , s h o w i n g numerous l a k e s a n d ponds, local r u g g e d m i c r o r e l i e f , and m a r g i n a l b e a c h and w a s h o v e r f a c i e s ; B: C a r e x - P u c c i n e l l i a and Elymus c o m m u n i t i e s and the landward l i m i t of m a r g i n a l washover sand 432 P a r t s o f c o r e t a k e n i n e p h e m e r a l pond n e a r edge o f s u p r a t i d a l f l a t s , showing ( a t l e f t ) near-surface interlaminated a l g a l mud, p e a t , and s a n d , and ( a t r i g h t ) p e b b l y sand washover u n i t a t a depth of 400 mm 433  xxxi i  160  Section t h r o u g h Babbage L a g o o n , Kay P o i n t s p i t , and P h i l l i p s B a y , s h o w i n g t h e d i s t r i b u t i o n o f s a n d and gravelly-sand lithofacies and the t r a n s g r e s s i v e c h a r a c t e r of t h e b a r r i e r sequence 438  161  Changes i n the King Point b a r r i e r , 1954-1972, s h o w i n g d e v e l o p m e n t o f an i n l e t - f i l l sequence by distal extension of the s p i t ; parts o f NAPL p h o t o g r a p h s A14363-54 (1954) a n d A22879-105 (1972) 440  162  A: low-level oblique photograph of surface morphology on t h e K i n g P o i n t b a r r i e r b a c k s h o r e , A u g u s t 1 9 7 5 ; B: R u n n i n g R i v e r d e l t a near Shingle Point, showing beach and washover f a c i e s a t t h e seaward margin of d e l t a i c s u p r a t i d a l f l a t s 441  163  Spring River barrier i n 1952 ( p a r t photograph A13383-155) and changes between 1952 a n d 1970  of NAPL occurring 442  164  Schematic diagram showing distribution of l i t h o f a c i e s forming s e q u e n c e b e n e a t h t h e Babbage D e l t a  hypothetical transgressive 445  xxxi ii  ACKNOWLEDGEMENTS  It  is a  individuals The  pleasure  to  and o r g a n i z a t i o n s d u r i n g  Sciences  received  from t h e N a t i o n a l  NSERC)  through  Division.  grants  of B r i t i s h C o l u m b i a . Geological  support  was  Laboratory I  of  contributions Council  of  study. Canada,  were  also  Canada  (now  t o Dr M. C h u r c h a n d f r o m t h e U n i v e r s i t y  a n d by a M a c M i l l a n provided  support  Family  by T e c h n i c a l  was  provided  by t h e  Postgraduate  Fellowship.  Logistical  F i e l d S u p p o r t S e r v i c e s , by  S h e l f P r o j e c t , a n d by t h e I n u v i k  wish  to for  express their  particular  as  criticism,  research  Research  supervisor,  and  f o r h i s concern,  the study,  t e c h n i c a l .support,  support  to  and  to  two  general  I am g r a t e f u l t o M. C h u r c h ,  and p e r s i s t e n t c o n f i d e n c e ;  in initiating  appreciation  wide-ranging  encouragement over t h e y e a r s .  part  many  (now I S R C ) .  individuals  acted  Major  Research  Personal  the P o l a r C o n t i n e n t a l  of  the course of t h i s  S u r v e y , by a N a t i o n a l R e s e a r c h C o u n c i l  Scholarship,  and  the help  p r o j e c t was s u p p o r t e d by t h e G e o l o g i c a l S u r v e y  Terrain  his  acknowledge  who  helpful  C P . Lewis, f o r  f o rinvaluable administrative  and f o r h e l p and c o l l a b o r a t i o n i n t h e  field. I Patricia  thank Bay,  F. S t e p h e n s o n , for provision  Institute of  c u r r e n t meters and f o r a s s i s t a n c e  water  of  Ocean  level  i n the f i e l d ;  Sciences,  r e c o r d e r s and D r J.W. M u r r a y ,  xxxiv  University  of B r i t i s h  L. V e t o ,  University  H. Wood,  Water  hydrometric  Columbia, f o r lending of  Survey  British of  equipment;  coring  Columbia,  Canada,  f o r SEM i m a g e r y ;  Inuvik,  times  very  especially grateful Stuart  Hotzel,  O'Loughlin.  involved  difficult  to B i l l  Annie  and  Barrie,  Krasker,  Important  Dr R. G i l b e r t ,  at  Linda  Roland  Wahlgren,  and  indebted  to  Helen  were  also  many  other  Kerfoot  a s s i s t a n c e w i t h l o g i s t i c a l problems, both field,  Gale,  and  by  individuals  Point.  and  John  made  I  f o r much in  I am  am  friendly  out  of t h e  and f o r s u b s t a n t i a l c o n t r i b u t i o n s t o t h e f i e l d d a t a .  Richard  Leslie  assistance. work  Ian  Krastman,  Kay  that  idyllic,  Forbes,  Michael  contributions  conditions  times  i n the c o a s t a l studies p r o j e c t at  especially  lending  analyses.  For major a s s i s t a n c e i n t h e f i e l d , under at  for  a n d Dr W. B l a k e , J r , G e o l o g i c a l S u r v e y  of Canada, f o r r a d i o c a r b o n  were  equipment;  provided  Audrey V y c i n a s  i n Vancouver.  analysis.  Naomi  technical  c a r r i e d o u t much o f t h e  Peter  Bergh,  valuable  Richards  Linda  helped  Forbes,  Julia  a d v i c e and laboratory  with  the t i d a l  Purcell,  and  Margaret R i t c h i e helped w i t h p r o d u c t i o n of t h e r e p o r t . I am g r a t e f u l project  and  encouragement. and  support  t o Dr B.C. M c D o n a l d f o r e a r l y  to  Dr  C.F.M. L e w i s  Finally, of  Dr  of the  for h i s interest  and  I am happy t o a c k n o w l e d g e t h e g u i d a n c e  J.R. M a c k a y ,  0. S l a y m a k e r ,  members  the U n i v e r s i t y  of B r i t i s h  i  support  Dr  W.H.  Mathews,  and  Dr  o f my r e s e a r c h s u p e r v i s o r y c o m m i t t e e a t Columbia.  1  1  INTRODUCTION  1.1 PREAMBLE 1.1.1 D E F I N I T I O N OF STUDY This  i s a study of water and sediment t r a n s f e r s i n a s m a l l  d e l t a - e s t u a r y of the southern It  i s an  investigation  Beaufort  of  Sea  an  (Figure 1).  s e d i m e n t s and geomorphology  t r a n s g r e s s i v e m i c r o t i d a l c o a s t under A r c t i c also  coast  conditions.  a n a l y s i s of s t r u c t u r e and v a r i a b i l i t y  local  It is  i n an e s t u a r i n e  s y s t e m , w h e r e i n e n e r g y a n d mass i n p u t s i m p o s e d by t h e and  on a  regional  environments produce a s s o c i a t e d o u t p u t s and storage  components. The p h y s i c a l c o n f i g u r a t i o n o f an e s t u a r y r e f l e c t s o f mass s t o r a g e  in  sedimentological hydrological  dynamically  interacting  subsystems.  subsystem  The  storage  h y d r o l o g i c a l and component  i s r e l a t e d t o water l e v e l  and  among o t h e r f a c t o r s , t h e n e t n o n - t i d a l c i r c u l a t i o n , effect The  of d e n s i t y s t r a t i f i c a t i o n storage  determines, estuary  in  and,  component large to  of  part,  the extent  o v e r t i m e , may y i e l d a p a r t i a l for  interpretation The  on c i r c u l a t i o n  the the  of the affects,  through the  i n the estuary.  sedimentological surface  patterns  subsystem  morphology  of  that a net gain i n storage historical  record  and  a  the  occurs model  of s i m i l a r a n c i e n t d e p o s i t s .  Babbage E s t u a r y  system e x h i b i t s d i s t i n c t i v e water and  2  FIGURE  1  Map o f t h e Y u k o n c o a s t , showing location of Babbage Estuary system and o t h e r t o p o g r a p h i c features, including major lagoons and e s t u a r i e s ( c o d e numbers d e f i n e d i n T a b l e 2 ) .  3  sediment  storage  characteristics setting.  patterns reflecting  These p r o v i d e ,  effects  of i c e , r u n o f f  context  in  Furthermore,  and  distinctive  i n some c a s e s , new i n s i g h t s regime, c o a s t a l of  development  they  indicate the r e l a t i v e  an  estuarine  of  The  Babbage  time  scales  significant  variability  10  range  1 2  s,  the  inferred The  corresponding  fluctuations  nature  response  of  at  these  (including  of  mass  to  system  system  high-latitude  related  to  the  components exhibits  r a n g i n g from 1 0 of  patterns  observed  3  to or  parameters. of  system  reaction-relaxation  and d i s t i n c t i v e  i t s transgressive,  s e t t i n g , a r e major  system.  system  scales  structure,  e f f e c t s , and s t o r a g e d i s t r i b u t i o n ) , the  for different  i n p u t s and system  fluctuations,  the  importance of v a r i o u s  variance  system.  into  s e t t i n g , and h i s t o r i c a l  the  estuarine  response  v a r i o u s a s p e c t s of t h e g e o g r a p h i c a l  s c a l e s of i n p u t and parameter the  system  f e a t u r e s of  microtidal,  or  themes o f t h e p r e s e n t s t u d y .  4  1.2 CONCEPTUAL  APPROACH  1.2.1 GEOPHYSICAL  SYSTEMS  Relationships  among  examined i n t h e c o n t e x t "of  components  relationships  or with  v a r i o u s g e o p h y s i c a l phenomena may be  of g e o p h y s i c a l  variables one  systems, s t r u c t u r e d sets  ... t h a t  another  exhibit  and  operate  discernible together  as a  complex whole, a c c o r d i n g  t o some o b s e r v e d p a t t e r n " ( C h o r l e y a n d  Kennedy, 1971, pp.1-2).  Geophysical  defined, with v a r i a b l e s having simple x(t);  system an  may  involve  intermediate  conditioned  by  system; and a  the  s y s t e m s may  different  variously  or l i k e dimensions.  an i n d e p e n d e n t o r i n p u t  operation  structure,  dependent,  be  or  or  response,  variable,  transformation,  parameters,  A  f,  and s t a t e of t h e  or  output  variable,  y(t)=f[x(t)]. Geophysical  systems  may i n v o l v e e n e r g y o r mass t r a n s f e r s  w i t h i n and between g e o g r a p h i c a l l y d e f i n a b l e p h y s i c a l they  may  involve structured geometrical, s t a t i s t i c a l ,  r e l a t i o n s h i p s among p h y s i c a l p r o p e r t i e s ; o r both. types  Chorley of  entities;  and  Kennedy  geophysical  morphological  system,  (1971)  they  may  involve  have d i s t i n g u i s h e d t h r e e  system:  the  and  process-response  the  or other  cascade  system,  the  system.  A  c a s c a d e s y s t e m , r e p r e s e n t i n g e n e r g y o r mass t r a n s f e r p r o c e s s e s , generally energy one  incorporates a chain  passing  from  subsystem  of  t o subsystem,  o r more s t o r a g e c o m p a r t m e n t s may  system  incorporates - a  subsystems,  occur.  with  mass  or  i n each of which A  morphological  s t r u c t u r e d s e t of p h y s i c a l p r o p e r t i e s ,  w h i c h may o r may n o t h a v e m o r p h o l o g i c a l  expression,  and  which  5  take  on  particular  interaction may  be  instantaneous  values  with  more  generality,  I n t e r a c t i n g parameter  and c a s c a d e  form  process-response  together  a  p a r a m e t e r s and represented  this  storage  by  system  Whitten  and  Sloss  (1964)].  morphological  of  terminology  system  parameter  system.  be c o n s i d e r e d in  cascade and  are  of  to  which  the  system  are  s t r u c t u r e s of t h e  (1971, in  figure  earlier  c o n c e p t s ' e n u n c i a t e d b y , among  others,  chapter 7),  Components o f t h e  Krumbein  parameter  geometry  (e.g. density  debt  1.3);  to  (1963,  or  ( 1 9 6 3 ) , and  system  or sediment albedo);  may  be  t e x t u r e ) or  most  parameter  include both.  C a s c a d e s y s t e m s may intervening  have m u l t i p l e  transfers  or  and K e n n e d y , 1 9 7 1 , p p . 5 - 7 ) . may  involve  i n p u t s and o u t p u t s .  transformations involve  l o c a t i o n s and d i s t r i b u t i o n c o n t r o l  output  the  components  (e.g. channel  non-morphological systems  result of  system,  [ c f . C h o r l e y and Kennedy  ' p r o c e s s - r e s p o n s e model' and  a  s y s t e m s may  product  individual  formulation  Krumbein  a  w i t h e n e r g y o r mass c a s c a d e s ; t h i s t y p e  termed,  parameter  as  The  various  terms or r e g u l a t o r s  transformation  from  r o u t e s , r a t e s , and  The  storage (Chorley input  to  interruptions  ( s t o r a g e ) , y i e l d i n g v a r i a b l e r e a c t i o n and r e l a x a t i o n e f f e c t s i n the  output  cascades,  (cf. Allen, the  transfer  s i z e - d e p e n d e n t ; as exhibit  :size  a  1974).  In  processes  result,  the are  of  deposits  s o r t i n g e f f e c t s , which c o n t r i b u t e to  The  identification  of  sediment  characteristically  sedimentary  d i f f e r e n t i a t i o n , while size-dependent l a g anticipated.  case  times  lags  is  may  commonly  lithofacies also  be  i n some c a s e s  6  d i a g n o s t i c a n d may c o n s t i t u t e [cf.  Stenborg  Allen  (1973) System  including  (1970)  valuable  finding  the  s t a t e of i n t e r n a l  number  v a r i a n c e , and f r e q u e n c y d i s t r i b u t i o n existence  In p a r t i c u l a r ,  of  thresholds,  transient  unstable  or  i n v o l v i n g a b r u p t s h i f t s o f t h e mean, may  give  frequency-dependent the  system  system  feedback  of  for linear  y(t) =  a  is  free some  systems linear  internal  effects  that are  of  is  of  s t a t i o n a r y and or  range,  then  theoretical  The o u t p u t o f a  i s g i v e n by t h e c o n v o l u t i o n  -h(x ) x ( t - x )dx ,  (1.2.1-1)  T  I n t h e f r e q u e n c y domain,  X ( f ) and Y ( f ) of x ( t ) and y ( t ) ,  unstable  i n p u t s , and i f t h e  may be a p p l i e d . system  single-input,  thresholds  range this  1971, p.31).  simple  system  responses,  where h ( ) i s a w e i g h t i n g f u n c t i o n a n d T i s a l a g t e r m domain.  lags.  variable  relaxation  cascading  within  physically-realizable  time  system  component  metastable  while  of  response i s l i n e a r w i t h i n  results  terms,  the c o m p l e x i t y of the  and P i e r s o l ,  process  physical  i f the  positive  l a g or  ( c f . Bendat  input  single-output, ergodic,  factors,  t h r e s h o l d s and feedback mechanisms i n t h e system  produce  trajectories  of  s t o r a g e and r e g u l a t i o n  system, and t h e i n t e g r a t i o n of v a r i o u s output  If  itself  f o r an e x a m p l e i n g l a c i a l h y d r o l o g y a n d  response behaviour r e f l e c t s a  the magnitude,  may  in  f o r examples . i n v o l v i n g s e d i m e n t a r y b e d f o r m s ] .  the  inputs,  a  i n the  the Fourier transforms,  are r e l a t e d through a frequency  response f u n c t i o n , H ( f ) : Y(f) = H(f) X ( f ) , where H ( f ) i s t h e F o u r i e r  transform  (1.2.1-2) of  MT).  The  modulus,  7  |H(f)| Mf), at  is  r  the  i s t h e phase  gain  factor  factor.  o f t h e system and t h e argument,  For a h y p o t h e t i c a l s i n u s o i d a l input  frequency f , |H(f)| i s the r a t i o of the output amplitude  the  input  system  amplitude  (Bendat and P i e r s o l ,  Frequency-dependent i n v e s t i g a t e d by t h i s rather theory  Mf)  and  stringent  and  complexity, example,  to  some  Amorocho  to  stationary  cover  satisfies  above.  Linear  multiple-input  can  be  applied,  systems  as  fixed-parameter  the  system  and  -output  with  well  B r a n d s t e t t e r , 1971).  geophysical  range of  throughout. sediment  listed  non-linear and  system  greater  (cf.,  for  I n any c a s e , t h e  system  response  with  beyond  some  inputs.  Most limited  i f the  approach  results are limited to  of the  s y s t e m r e s p o n s e c h a r a c t e r i s t i c s c a n be  assumptions  the  shift  1971, p.41).  strategy  c a n be e x t e n d e d  systems  d e f i n e s t h e phase  to  In  input an  systems  are  conditions  energy  non-linear  and  many  to  represent  non-linear  c a s c a d e between c o u p l e d water and  c a s c a d e systems, water and sediment  considered  are  parameters  system t h a t forms t h e c o u p l i n g .  In  of  transfers  may  be  the process-response  general,  t h i s , system  is  non-linear, v i z . : b  J = aQ +c+e, b * l , where  J  discharge, error  is  the  transport  rate,  Q  is  t h e water  a , b, and c a r e e m p i r i c a l . c o e f f i c i e n t s and e  or variance  the exponent discharge  sediment  term.  i s typically  (db/dQ^O;  see  i s an  For bedload transport, i n p a r t i c u l a r , very  high  section  (b>>l)  and  4.1.2).  In  dependent  on  the  of  case  8  suspended  sediment t r a n s p o r t , because J = C O  where C  S  sediment  concentration,  dC /dQ=0 ( i . e . i f t h e s  the  exponent  concentration  i t is  found  i s the S  b=l  i f and  only  i s constant).  natural  systems,  that  suspended  sediment v a r i e s as a p o s i t i v e  the  In  i f many  concentration  of  l o g a r i t h m i c f u n c t i o n of  d i scharge, ln(C ) s  and  the  J=f(Q)  logarithmic  = a l n ( Q ) + c + e, system  transformation  may  be  treated  as  linear  ( c f . Sharrna a n d D i c k i n s o n ,  after  1979).  9  1.2.2 ENVIRONMENTS AND F A C I E S An  environment  phenomena a f f e c t i n g inputs  to  a  may be v i e w e d a s t h e t o t a l i t y the n a t u r e and time-space  system  and  sense, t h i s d e f i n i t i o n external The  and  constraints  involves  one i n t e r n a l  in  which  the  distribution  on i t s r e s p o n s e . parameter  of In a  systems,  one  t o a g i v e n p r o c e s s - r e s p o n s e system.  e x t e r n a l parameters a r e  systems  two  of e x t e r n a l  part  of  g i v e n system  larger  process-response  i s imbedded; t h e i n t e r n a l  parameters c o n s t i t u t e the parametric  component  of  the  given  system. A  sedimentary  environment  h a s been d e f i n e d a s a " c o m p l e x  of p h y s i c a l , c h e m i c a l , and b i o l o g i c a l c o n d i t i o n s under sediment cf.  accumulates"  (Krumbein  S c r u t o n , 1960, pp.92-93).  environment  and  sedimentary Moreover,  In  associated  close  system  as  may  has  be  classified  evolutionary  a  p.324;  sedimentary  equivalent defined  to  a  above.  sedimentary environment  and t h e  system.  l o n g been r e c o g n i z e d t h a t l a n d s c a p e s a n d d e p o s i t s  or  into  or  (1838)  the  introduced  stratigraphically  distinctive  stratigraphic  environmental context  lithology  1963,  a  r e l a t i o n s h i p e x i s t s between t h e  s t o r a g e components of t h e s e d i m e n t a r y It  sense, are  functional  geomorphology of a p a r t i c u l a r  this  Sloss,  sediments  process-response a  and  which  not  p o s i t i o n , but a l s o  associated term  equivalent units  or palaeontology.  groups,  process  'facies' that  only  i n terms of  sets. to  differ  by  Gressly  distinguish laterally  The f a c i e s c o n c e p t h a s s i n c e  in been  10  broadened  to  include  environmental  attributes  stratigraphic  context.  morphological  or  subsystems, and subsystems  sedimentary but Facies  within  the sediment  characteristics  transport  Singh,  attributes  sets  of  1973; may  be  also  usefully  assemblages limited  Blatt  derived  of  particle  size,  of  this  ( 1 9 7 7 , 1978)  for application  to  braided  form  adopted  structural  1972,  from  or o t h e r  classification  generate  4.4.1).  These various  them.  of  defined  by  a  compositional criteria.  k i n d , d e v e l o p e d by river  They  distinctive  deposits,  f o r t h e p r e s e n t s t u d y i n an amended and  (see s e c t i o n  chapter  by u s e o f  specified  structural characteristics,  these  1979).  terms  lithofacies  been  and  et a l . ,  described  in  cascade  of  usually  Walker,  summarized  the  cascade.  of s t a n d a r d l i t h o f a c i e s t y p e s , each  range  properties,  be  in a  as  components  textural  and  r a t i o - s c a l e m e a s u r e s and s t a t i s t i c s may  related  viewed  environments  ( s e e , f o r example,  and  lithological  be  common  p r o d u c t s of i n d i v i d u a l  depositional  deposits having d i s t i n c t i v e  Reineck  may  depositional  sharing  necessarily  i n p a r t i c u l a r as s t o r a g e  Distinctive  6;  not  sets  A  Miall has  expanded  11  1.2.3  ESTUARINE SYSTEMS An e s t u a r y o r e s t u a r i n e s y s t e m may  phenomena  caused  widely  Pritchard  cited  (1963)].  [this  definition  As  coastal  formulation  proposed filters  by  i s simpler  Cameron  through which  and  runoff  e n t e r s the s e a , e s t u a r i e s form p a r t of a r e l a t i v e l y minor i n the g l o b a l h y d r o l o g i c a l cent  of t o t a l  system, p a s s i n g o n l y about  precipitation  o c c u r r e n c e of c o o s c i l l a t i n g density  of  by o r p e r t a i n i n g t o t h e i n f l o w o f f r e s h w a t e r  r u n o f f t o an o c e a n o r m a r g i n a l s e a than the  be d e f i n e d a s a s e t  (More, 1967). t i d e s , due  seven  H o w e v e r , due  to  the  link  to the  difference  b e t w e e n f r e s h w a t e r r u n o f f and s e a w a t e r , and due  per  in  to the  e x t r a o r d i n a r y v a r i e t y of c i r c u l a t i o n p r o c e s s e s which o c c u r as a r e s u l t o f t h e s e and o t h e r e f f e c t s , complex  hydrological  sediment  traps  ecological  and  systems.  ( c f . Meade,  estuaries  form  These systems  1969)  socioeconomic  and  are  importance  remarkably  frequently of  form  considerable  (cf. Officer  et a l . ,  1977). Periodic feature  of  tidal estuarine  during a given tide certain  storage  the  tidal-current  meteorological 1924;  parameters  potential hydraulics.  adjustments  The  is  to  (cf. Pattullo  of water range  the  estuary,  volume  Non-periodic various  characteristic  tidal  of  storage  a  volume  i s a f u n c t i o n of the  f l u c t u a t i o n s o c c u r due steric  water  systems.  morphological  determine  of  other  and  of  which  and  control  water  storage  effects,  et  al.,  1955;  f o r c i n g processes (see,  for  example,  Proudman, 1955;  stored  including  Beal,  1968),  Doodson,  S m i t h , 1979; Wang, 1 9 7 9 ) , and c h a n g e s i n  12  t h e b a c k w a t e r c u r v e due (Volker,  1966).  to  Individual  importance  of  significant  s e a s o n a l and  of  the  v a r i a n c e may  freshwater estuary regime  and  differ  storage  other  discharge  i n the  other  system  with  i n the  long-term  indeed,  distribution  Furthermore,  water  parameters.  respect to flushing  relative  components;  fluctuations  o r v o l u m e of r u n o f f  river  stored  h i g h l y v a r i a b l e , d e p e n d i n g on t h e  b e t w e e n s h o r t - and other  of  occur w i t h i n a g i v e n system.  be  implications  systems  various  fraction  may  fluctuations  This  in  the  circulation  has  r a t e s and  the  important  the  partition  s t o r a g e of suspended sediment  and  pollutants. E s t u a r i n e s y s t e m s commonly s t o r e l a r g e v o l u m e s o f  sediment,  i n a v a r i e t y of d i s t i n c t i v e d e p o s i t s , i n c l u d i n g m a r i n e - d e l t a i c , intertidal, 1967;  barrier,  H a y e s , 1975;  suspensions, and  Allen,  and  F r e y and  1957;  represent  estuarine  tidal 1970;  motions Nelson,  Allersma et a l . , a  form  ( c f . Postma,  in  fine-sediment  and  1970;  ( c f . Bagnold,  1966).  1966;  K i r b y and  (Inglis  Parker,  o f s h o r t - o r medium-term s t o r a g e .  including  ( c f . Bates,  water  and  facies  i n many d e l t a s i s s i g n i f i c a n t l y  effects,  by  water  marsh  B a s a n , 1978)  1953;  Wright,  Sediment t r a n s p o r t i n primarily  and  w h i c h can a c h i e v e v e r y h i g h c o n c e n t r a t i o n s  d e p o s i t i o n a l product by  lagoon,  1970; the  sediment  is  1976).  estuarine  system  energetically-coupled cascading  is  a s s o c i a t e d energy appropriate  transport subsystems.  and  and  Coleman e t a l . ,  Galloway,  therefore  The  influenced  stratification  S c r u t o n , 1960;  m o t i o n s and It  density  1977)  powered  dissipation to  storage  Although  treat as  sediments  13  are predominantly as  a  result,  respond  c o n s e r v a t i v e , sediment  to  a  structural  Furthermore,  given  input  event.  similarities  sediment  morphological sedimentary  are  can  be  anticipated.  s t o r a g e phenomena d e t e r m i n e  parameters  of the h y d r o l o g i c a l  f a c i e s o r f a c i e s a s s e m b l a g e s may  present study  system,  characterized  radiation, thesis  i s concerned by  great  extreme temperatures  of  the  present  in  part  subsystem,  be  work  studies  Arctic  Arctic  estuarine  environment  al.  (1974), Barber  and  Burrell  Ford  (1971), Ince  (1962), Kinney  Knight  Church  and  and et  (1970),  (1977),  and  al.  1973,  An  1974),  approach  distinctive  set  Burrell  and Wiseman  et  Dygas  Knight  (1971),  and W a l k e r  (1973),  Lewellen  (1963a),  (1977),  Matthews  Walker  (1979,  Bruder  in  (1972),  (1969,  1971,  (1979).  t o A r c t i c e s t u a r i n e systems as a involves  the  (1972),  M o r i s o n and T a y l o r ( 1 9 7 8 ) , R e i m n i t z and  1972,  of  (1972),  press),  and  comprehensive investigation;  Reimnitz  Lewis  (1979), Tucker  and  H a t t e r s l e y - S m i t h ( 1 9 6 5 ) , Hume  Lake  Mackay  a  estuaries  aspects  (1973),  Short  is  i n c l u d e r e p o r t s by A l e x a n d e r  (1968), Barnes  (1976),  net  dynamic  few  contributions that deal with various physical  of It  be a s s o c i a t e d w i t h  this  with  estuarine  ice.  distinctive  e s t u a r i e s have p r e c e d e d  while  cascade.  variance  Relatively  the  identified  Arctic  abundant  that  i n s u c h an e n v i r o n m e n t . of  an  seasonal  and  m o r p h o l o g i c a l c h a r a c t e r i s t i c s may occurring  with  may  Nevertheless,  g e o g r a p h i c a l l y d e f i n e d subsystems of the h y d r o l o g i c a l The  not;  s e d i m e n t o l o g i c a l and h y d r o l o g i c a l s u b s y s t e m s  differently  certain  suspensions  certain  assumptions  potentially about  the  14  relevance of g l o b a l - s c a l e hydrodynamic  systems.  variability  Global-scale  or C o r i o l i s e f f e c t s and solar  t o t h e mechanics of variables  include  inertial  energy  sources,  notably  large-scale  r a d i a t i o n and g r a v i t a t i o n a l p o t e n t i a l energy.  potential exhibits  some l a t i t u d e - d e p e n d e n c e a n d  A r c t i c Ocean a r e g e n e r a l l y semidiurnal. latitudes  small  and t h e i n e r t i a l  high-latitude that,  radiation  operating  distinctive  features  ultimately  The  i n t h e s o u t h e r n B e a u f o r t Sea  (Sverdrup,  regime  1926).  exhibits  in  the  estuarine  of h i g h - l a t i t u d e  Finally,  a pronounced  of  a  Strahler,  interpreted  in  assemblage  the estuarine  annual  implies  terms  of  the  and i n t h e p a t t e r n  input  Most  an  be  regime.  depositional assumption  of  sedimentary environment, broadly i n erosional  consistent  process-response  stationary  of  systems can  systems ( s e e ,  1950; L a n g b e i n and L e o p o l d , 1964).  constant-parameter statistically  estuarine  quasi-homogeneous  analogous t o concepts of e q u i l i b r i u m  regime.  B o t h may be  behaviour system  of  under  Changes i n  the  a a  system  o f i n t e r n a l s t o r a g e may o c c u r due t o  c h a n g e s o f s y s t e m p a r a m e t e r s , w h i c h may be due t o effect  the  environment.  t o t h e r a d i a t i o n and t e m p e r a t u r e  recognition  equilibrium  output  i n the  i n a m p l i t u d e and p r e d o m i n a n t l y  period  in  product or l i t h o f a c i e s  e.g.,  tides  tidal  d i r e c t l y or i n d i r e c t l y , a f f e c t s a great v a r i e t y  processes  ascribed  The  C o r i o l i s e f f e c t s are p a r t i c u l a r y strong at higher  is approximately semidiurnal  cycle  small  o r may r e s u l t f r o m n o n - s t a t i o n a r i t y  a  threshold  o f one o r more  input  variables. Non-stationarity  of inputs  a r i s e s due t o c h a n g e s i n o t h e r  15  TABLE  1  Scales  of v a r i a n c e  class  characteristic  s ub d i u r n a l  turbulence g r a v i t y waves  diurnal  t i d a l and variance  s d a  {  seconds d ay s years  systems  process  diurnal  per±od_ 3 T<10' 10  3  <T<10  0.01<T<  synop t i c  cyclonic  seasonal  earth  annual  year-to-year variance of h e m i s p h e r i c circulation  decadal  short-term variance  millenial  long-term changes  macro-  mega-  estuarine  _s c a l e  micro-  meso-  in Arctic  systems  orbit  5  2  2<T<100 100<T<366  climatic climatic  1<T<  10  10<T<100 T>100  «  16  cascade  systems  consideration. as  a  that  For example,  result  of  the  it  system  under  s o r t may  occur  f l u c t u a t i o n s , changes i n l a n d - u s e ,  or e r o s i o n a l t h r e s h o l d s .  changes,  stationarity  with  a d j u s t m e n t s of t h i s  climatic  tectonic a c t i v i t y , discrete  interface  appears  that  f o r any g i v e n i n p u t s e r i e s  Apart the  from  definition  depends  on  the  such of time  o  scale 1965;  considered Mandelbrot  s y s t e m may weeks,  or  years,  For  1974,  and W a l l i s ,  be s t a t i o n a r y  corresponding to variance.  (Bath,  but tidal,  period  1969).  over  of  estuarine  few  minutes,  non-stationary  over  intervals  seasonal,  or  longer-term  of t h i s work, t h e t i m e s c a l e of a  the  characteristic,  ( i n v e r s e f r e q u e n c y ) and  i n Table 1 i s employed.  i n p u t s t o an  Lichty,  a  synoptic,  the purposes  The  intervals  highly  process i s taken to connote modal  p.108; c f . Schumm and  dominant,  or  the terminology presented  17  1.3 THE PRESENT STUDY 1.3.1 BABBAGE ESTUARINE SYSTEM The  e s t u a r i n e system a t  the  confluence  of  the  Babbage  R i v e r a n d Deep C r e e k , on t h e c e n t r a l Yukon c o a s t n e a r Kay P o i n t (69°18'N, 138'24'W;  see  F i g u r e 1 ) , was c h o s e n a s t h e f o c u s o f  the p r e s e n t i n v e s t i g a t i o n . under  The p r o j e c t was i n i t i t i a t e d  i n 1974  t h e a u s p i c e s of t h e G e o l o g i c a l Survey of Canada, t o g e t h e r  w i t h a companion s t u d y d e s i g n e d t o examine a s p e c t s erosion,  nearshore  the v i c i n i t y combined  sediment  o f Kay P o i n t  of  coastal  t r a n s p o r t , and beach dynamics i n  (Lewis, 1975).  Early  r e s u l t s of  i n v e s t i g a t i o n were r e p o r t e d by L e w i s a n d F o r b e s  the  (1974,  1975). The  major  illustrated  the  The  transgressive,  Babbage  setting and  E s t u a r y system a r e  can  be  microtidal,  f e t c h and a h i g h l y v a r i a b l e n i v a l  barrier-spit Kay  of  i n F i g u r e 2.  low-Arctic, restricted  features  some  summarized with  runoff  seasonally regime.  4.4 km i n l e n g t h e x t e n d s s o u t h w e s t w a r d  Point, p a r t i a l l y  enclosing  an  extensive  as  shallow  A from  lagoon  ( F i g u r e 3 ) . Depths  i n t h e lagoon average about 1 m r e l a t i v e t o  mean  A l o n g narrow  water  level.  t r a n s e c t s t h e main tidal  inlet  lagoon  occurs  basin.  inlets  t o time near the p r o x i m a l  end.  to  as  small,  t o the b a r r i e r quasi-permanent  end o f t h e b a r r i e r  (M2,  ( d e n o t e d M3) d e v e l o p f r o m  time  A  major  inlet,  2 km  t h e e s t u a r y e n t r a n c e o r main e n t r a n c e  ( M l ) , l i e s between Niakolik Point.  A  toward the d i s t a l  F i g u r e 2) a n d s h o r t - l i v e d  referred  shoal p a r a l l e l  the  distal  This inlet  end  of  Kay  Point  wide, section  spit  i s c h a r a c t e r i z e d by a b r o a d  and  central  FIGURE 2 Map of the Babbage E s t u a r y system, showing m a j o r s a m p l i n g s t a t i o n s , l o c a t i o n s of t i d e and s t a g e r e c o r d e r s , h y d r o m e t r i c s e c t i o n s , and the l o c a t i o n of t h e m e t e o r o l o g i c a l s t a t i o n a t Kay P o i n t (see F i g u r e 1 f o r r e g i o n a l s e t t i n g ) .  19  FIGURE 3 Bathymetry of Babbage E s t u a r y i n 1975 and view across main entrance s e c t i o n toward Kay P o i n t s p i t with Babbage Lagoon to r i g h t , Kay Point in d i s t a n c e , and N i a k o l i k P o i n t in foreground.  20  platform about  and  two  2 m a t mean Supratidal  marginal  channels,  w i t h maximum d e p t h s o f  tide. (storm-flood)  surfaces  are  found  at  n o r t h e a s t and s o u t h w e s t e n d s o f t h e l a g o o n ; s u p r a t i d a l the  Babbage  entrance  Delta  extend  section.  fluvial  Four  across major  the  valley  distributary  d i s c h a r g e a c r o s s the d e l t a  the  flats  of  opposite channels  to the lagoon.  The  the carry  largest  of t h e s e , r e f e r r e d t o as t h e main d i s t r i b u t a r y c h a n n e l , can identified Extensive  in  Figure 2  intertidal  by  the  line  of  p a r t of the d e l t a p l a i n are  connected  subaerial  limit  area  by  narrow  Creek,  distributaries  delta.  The  (Figure 5).  the  Babbage  lower  Babbage  of  River  by  in  the  and  4B).  some o f  t o t h e main  total  subaqueous below  o v e r 40 two  these  distributaries  lower  valley  (Figure 2).  i s a sinuous g r a v e l - b e d stream w i t h a The  alternating  km . 2  non-tidal  above  the  The  low-Arctic  o r p o i n t b a r s , by pool-riffle  to  lower  c h a n n e l i s l o c a l l y d i v i d e d and lateral  the  f r o m t h e B a b b a g e , f o r m an  b a r s i n some r e a c h e s , a n d by a p r o m i n e n t (Figure  The  large  of storm-surge backwater extends upstream  n i v a l d i s c h a r g e regime. dominated  channels  is a little  River,  f l o w i n g t o Deep C r e e k  limit  A  o f t h e d e l t a and l a g o o n c o m p l e x  anastomosing channel system  the  tidal  of r e c e n t storm-surge f l o o d i n g Deep  (Figure 4A).  i s o c c u p i e d by l a k e s and p o n d s ,  d i s t r i b u t a r y c h a n n e l network and  stations.  s u r f a c e s o c c u r on t h e l a g o o n m a r g i n o f t h e  d e l t a p l a i n and l o c a l l y w i t h i n t h e d e l t a  which  sampling  be  is  diagonal sequence  FIGURE 4 A: i n t e r t i d a l and s u p r a t i d a l s u r f a c e s of the Babbage D e l t a , w i t h main d i s t r i b u t a r y c h a n n e l i n d i s t a n c e , S e p t e m b e r 1976; l a g o o n i s o u t o f the p i c t u r e t o the r i g h t ; B: lower Babbage R i v e r , l o o k i n g downstream t o w a r d h y d r o m e t r i c s e c t i o n B l , 2 A u g u s t 1974.  22  FIGURE 5 Babbage D e l t a and southern lagoon, showing c o o r d i n a t e system, i n t e r t i d a l t r a n s e c t s ( ), s i t e s where s e d i m e n t a c c u m u l a t i o n was m e a s u r e d on t h e d e l t a p l a i n ( # ) and on i c e (OK l o c a t i o n s of sediment traps (0 ) , excluding traps i n the northern l a g o o n ; p a r t o f NAPL p h o t o g r a p h A22975-55, 4 August 1972. a  n  d  23  The  estuarine  system as d e f i n e d  laterally  bounded  by  delimited  at  marine  entrance the  the  the  s e c t i o n (the  limits  of the  hydrometric  pre-Holocene end  ( F i g u r e 2)  on  the  distributary.  and  At by  Section  the Tulugaq  main  the headward  end,  the  a  grid  intervals. to  the  w i t h two  ( a l s o known a s t h e  Crow).  (Figures 5  and  Six-digit  coordinates  (xxxyyy)  Standard  d e l t a for r e g u l a r sampling  of  p r o p e r t i e s and  water in  Figure  meteorological level  located  6.  procedures presented appendices  A brief is where (A.3,  'Tulugaq River' on many maps.  also  summary  given  in  of  A.8,  the  referred  l i n e s a t 500-m  in. s i t u  positions  observations  and  locations  the  within  of  s e c t i o n s , and  other  observation A.2; the  of  are the  water  l o c a t i o n s f o r which  i s a v a i l a b l e are  Appendix  appropriate A.4,  been  identify  includes  s i t e s and  information  km  1  with  and  of h y d r o m e t r i c  Drillhole  stratigraphic  5  suspended sediment c o n c e n t r a t i o n s  which  station,  recorders.  shallow Figure  2,  above  s t a t i o n s e s t a b l i s h e d i n the  l a g o o n and  shown  1  50 m.  6),  of Deep  major t r i b u t a r i e s ,  network  nearest  locations  was  P o s i t i o n s w i t h i n the e s t u a r i n e system have to  and  the  ( F i g u r e 4B),  BI  is  surface  t h a t were e s t a b l i s h e d on  t h e Babbage R i v e r a t BI  downstream from the c o n f l u e n c e  study  P o i n t s p i t and  system are determined  C r e e k a t D l and  Trail  by Kay  upland  'marine b o u n d a r y ' ) .  sections  uppermost  f o r the present  indicated in program  further text  and  and  details in  are  other  A.12).  i s the o f f i c i a l  name, b u t  'Crow R i v e r '  appears  24  FIGURE 6 Babbage Estuary system, showing g r i d network and l o c a t i o n s of b o r e h o l e s , s h o r t cores, and exposures.  25  The  cascade  subdivided  into  intertidal,  of  fluvial,  lagoon,  subsystems. terms  system  The  the  Babbage  tidal-distributary, marginal supratidal,  s t r u c t u r e of the system  and  may  subsystem  may  environment  or,  encompass a  number  be  viewed  depending of  as  upon  a  the  be  subenvironments.  subsystem  i n c l u d e s , c h a n n e l and o v e r b a n k  channel  subsystem  includes  e n v i r o n m e n t s and may  be  closure;  plain  the  supratidal  flats,  intertidal intertidal criteria; flats,  delta  extended  ephemeral  subsystem  be  protected basin finally,  the  back-barrier platform  fluvial tidal  channel-margin  include  lakes  without  the  be  and l a k e s w i t h c l o s u r e ; divided  into  high  and  f r e q u e n c y or o t h e r  ephemeral  ponds,  environments; the lagoon  exposed  lagoon  encompasses  and  subsystem  ('open-estuary'),  lagoon shoal environments;  components.  low  includes vegetated supratidal  closure,  ( ' l a g o o n ' ) , and barrier  to  ponds,  the marginal s u p r a t i d a l  into  the  environments; the  s u r f a c e s on t h e b a s i s o f e x p o s u r e  subdivided  be seen  low  can  beach and washover  subsystems.  may  and  in  i n c o r p o r a t e s v e g e t a t e d h i g h and  l a k e s w i t h and w i t h o u t  marginal  to  barrier  depositional  Thus,  channel  be  examined  single scale,  may  delta-plain,  of t h e v a r y i n g n a t u r e of l i n k s between t h e s e  Each  can  Estuary  foreshore,  backshore,  and, and  26  2 REGIONAL CONTEXT: NORTHERN YUKON AND BEAUFORT SEA  2.1 GEOGRAPHY AND PALAEOGEOGRAPHY 2.1.1 CONTEMPORARY GEOGRAPHY The  present  illustrated  configuration  i n F i g u r e 1.  Mackay  (1960),  (1973), Lewis and Forbes  the  Previous  i n c l u d e s u r v e y s by F r a n k l i n (1948),  of  (1828),  Hughes  Yukon  general  O'Neill  (1972),  (1924),  the  Backhouse R i v e r  Bostock  and  (1974a,  The c o a s t i s c o n t e r m i n o u s w i t h t h e n o r t h A l a s k a  near  Lewis  i n press).  coast  i n the  i s l e s s t h a n 10 km w i d e  (Figure 7A); further east, the p l a i n  e x p a n d s t o a p p r o a c h 40 km i n w i d t h n e a r t h e Babbage R i v e r . coastal plain  i s f l a n k e d on t h e s o u t h by t h e B r i t i s h ,  R i c h a r d s o n M o u n t a i n s , p a r t s o f t h e Romanzoff U p l i f t Arch  (Norris,  1973),  n o r t h e r n Yukon The  Coastal  flysch,  sediments.  elevations  up  Plain  i s underlain  molasse,  Palaeozoic  and  Babbage R i v e r b a s i n  metaclastics  of  B r i t i s h Mountains, (Tulugag  Barn, and  and A k l a v i k  1600 m  i n the  elastics  and  including  i n c l u d i n g p a r t s of t h e 1963).  Formation  parts  of  and T r a i l ) b a s i n s ; c r y s t a l l i n e  clastic  carbonates occur i n the  (Norris et a l . ,  t h e Neruokpuk  by J u r a s s i c a n d  epicontinental  R i c h a r d s o n , Barn, and B r i t i s h mountains, upper  to  The  ( F i g u r e s 7 and 8 ) .  Yukon  Cretaceous  with  is  investigations  McDonald  ( 1 9 7 4 ) , a n d Rampton  w e s t , where t h e s u b a e r i a l c o a s t a l p l a i n  coast  Precambrian  a r e exposed  the western  i n the Babbage  i n t r u s i v e s of Devonian  FIGURE 7 Western part o f Yukon C o a s t a l Plain with British M o u n t a i n s i n b a c k g r o u n d ; A: B a c k h o u s e L a g o o n ; B: F i r t h R i v e r f a n w i t h N u n a l u k L a g o o n in foreground.  28  FIGURE 8 A: h e a d w a t e r s o f Babbage R i v e r with Tertiary pediment and i c i n g , 29 A u g u s t 1 9 7 6 ; B: u p p e r T r a i l River basin i n B r i t i s h Mountains near Mount S e d g e w i c k .  29  age  are  f o u n d a t Mount S e d g e w i c k  ( N o r r i s e t a l . , 1963; An  extensive  mountains  h a v e a mean (Rampton,  press),  height.  The  the  east  the  predominantly  Further  east,  B a b b a g e , R u n n i n g , and the  coastal  major  Blow) are  plain,  (Figure  on  (Figure  the eastern  rivers  depth  of  and  the c o a s t a l p l a i n ,  north  (notably  incision  7B),  Alaska Spring,  i n c i s e d below the g e n e r a l  the  the 7A),  I s l a n d (Malcolm  to the coast  fans along  the  west of  4  i t e x c e e d s 30 m i n  aggradational  extensive  7.5x10"  River  l a r g e fans that extend north  coast.  about  Blow  forming  the  beds  high  are  to  underlying  10 m  major r i v e r s west of H e r s c h e l  similar  into  than  Firth)  of  of  1972;  t o w a r d and  such t h a t the c o a s t a l b l u f f  near  basin  (Hughes,  s u r f a c e and  northwest  i s generally less  the  pediment  this  toward  River  1980).  from the c o a s t a l p l a i n  ( F i g u r e 8A);  in  in  rises  slope  Malcolm River while  Pelletier,  post-Palaeocene  Rampton, i n p r e s s ) the  i n the upper T r a i l  level  increasing  eastward. Permafrost excepting  large  (J.R. Mackay, Lachenbruch, Beaufort  i s continuous l a k e s , and  personal 1973,  Sea  b e n e a t h most s u b a e r i a l  surfaces,  e x t e n d s t o d e p t h s o f 600  m o r more  communication,  p.10).  shelf  I t occurs  (Mackay,  Widespread  massive  40000 y e a r s  (Mackay e t a l . , 1972,  and  exposures,  other  erosional  impact  i  •  ground  1972;  where  (Figure  ' •  9).  ice,  1981;  et  al.,  processes  in  exert  the  1978).  of which i s o l d e r  p.1322), outcrops  thaw  and  a l s o under p a r t s of Hunter  some  c f . Gold  than  coastal a  major  FIGURE 9 Massive ground i c e in i c e - t h r u s t sediments e x p o s e d between Kay P o i n t and King Point, M a c k e n z i e Bay c o a s t ; A: A u g u s t 1977; B: A u g u s t 1975.  31  The  Yukon C o a s t a l P l a i n  characterized  by  wet  i s an a r e a o f  sedge  meadows  tundra  in flat  tussock  t u n d r a on s i t e s w i t h b e t t e r d r a i n a g e  1971).  Low s h r u b w i l l o w ( S a l i x  B. g l a n d u l o s a ) (especially  are  locally  particularly  in  Delta,  which  depression, (Yorath,  developed  trending  canyon, break is  at a depth  to  Delta, 100 m  submarine  a  the of  shelf  about  depression  the  scoured  increasing  ridge,  same  with  known  to  structural faulting  seaward t o Mackenzie  to  (Shearer,  1972)  intersect  400 m.  East  the  of t h e  w i d t h o f a b o u t 100 km t o t h e s h e l f  50 km w i d e .  the  Spruce  Mackenzie  block  b o x - l i k e trough  across  f r o m Kay P o i n t n o r t h w e s t  Bay.  by  Depths near  the  shelf  the coast are highly  b e i n g l e s s t h a n 10 m i n t h e e a s t o v e r  Mackenzie  riparian  1974) and i n t h e upper  glacially  infilled  has  willow  Valley  o f a b o u t 70 m; w e s t o f t h e c a n y o n ,  approximately  variable,  and  shelf  of  Firth  late-Cretaceous  slope a t a depth  the  shrub  Creek.  a  by  northwest  continental  lower  This depression extends  Canyon a s a p a r t i a l l y  Rigby,  ( B e t u l a nana a n d  element  i s b o u n d e d on t h e e a s t  occupies  1973).  the  (Wein e t a l . ,  Babbage R i v e r b a s i n a t S p r u c e Yukon c o a s t  major  and  on t h e e a s t e r n c o a s t a l p l a i n .  30 km o f t h e c o a s t  The  (Welsh  abundant, w h i l e t a l l  (Picea glauca) occurs l o c a l l y within  a r e a s a n d sedge  sp.) and b i r c h  Salix alexensis) i s a  vegetation,  vegetation,  the  subaqueous  t o 50 m w i t h i n 10 km o f Kay P o i n t  distance  o f f Herschel  Island.  a maximum d e p t h o f a b o u t 14 m,  extends  to Herschel Island, separating a  informally  as H e r s c h e l B a s i n from  H e r s c h e l B a s i n s h o a l s toward  the southeast  A  deep  Mackenzie  and the waters  32  of P h i l l i p s  Bay,  w i t h depths  i n t h e r a n g e 5-7  The 250  total  km.  cliff  Of  o f f t h e Babbage E s t u a r y , a r e g e n e r a l l y s h a l l o w  length  this,  developed  fronted  by  67  narrow beach  length  to  largest. ^100  m  m;  7  more  20  may  be  km  r a n g i n g from n a r r o w and  to  systems  particularly  the area d r a i n i n g potential  the  f o r Yukon  2  respond  from  among  the  length  from  inlets),  with  z e r o t o more t h a n  one.  (mean w i d t h l e s s  than  low m).  are  strongly  during AJ_,/AD,  to the lagoon snowmelt  and  influenced following  where system,  runoff  deeper submerged-valley  by the  i s lagoon  AL  provide  impact  on  a l t h o u g h t h e h y p s o m e t r y of t h e d r a i n a g e  i m p o r t a n t and  expected  behind  is in  (including  V a l u e s of t h e r a t i o  e s t u a r i n e system,  features.  2.  range  than  runoff,  of  remainder  data  systems  Many o f t h e l a g o o n  measure  present  Morphometric  mean berm h e i g h t l e s s t h a n  D  are  barrier  m,  rough  lagoons  The  i s approximately  Estuary  200  A  shoreline  coastal  sediments,  inlet  Babbage  b a r r i e r s are t y p i c a l l y  a r e a and  tidal  are given i n Table  length ratios  snowmelt season.  9).  the  2  The  freshwater  approximately  have been c a t a l o g u e d , r a n g i n g i n a r e a  Individual  inlet/barrier  barrier  lagoons  4.5x10  to  of  (Figure 10).  Twenty l a g o o n s 4  is  ( F i g u r e s 7A and  shallow  barriers  c o a s t b a r r i e r s and  6.8x10  coast  b a r r i e r - l a g o o n , and  Extensive  coastal  Yukon  i n frozen unconsolidated Quaternary  a  combined km.  the  some 58 p e r c e n t t a k e s t h e f o r m o f a  c o n s i s t s of d e l t a i c , The  of  m some 3 km o f f s h o r e .  estuaries  i n a manner d i f f e r e n t t o t h a t o f  a the  basin  can  be  shallow  FIGURE  10  Barriers and l a g o o n s a t S t o k e s P o i n t (A) at King Point (B), c e n t r a l Yukon c o a s t ; A u g u s t 1976; B: A u g u s t 1975.  and A:  TABLE  2  Morphometry  of  l a g o o n s and  8  9 10 11 12 13 1A 15 16 17 18 19 20  .  , d  A  I  Clarence Backhouse Mai c o l m - 1 Malcolm-2 Nunaluk Workboat Pauline Ptarmigan un-n ame d Whale r i a- 1 Ro l.an d S t okes-1 Stokes-2 Spring-Phillips Babbage King ria-2 r i a- 3 Shingle  3 .2x10* 1 .9x10^ 2 .8x10* 1 .4x10° 1 .5x10 ' 4.5xlo' 2 .6x10^ h. 1 x 1 0 * 9 .0x10, 2 .3x10* .1 • f t J. . 8 x 1 0 ° 1 .9x10° 6 • 6 1 .6x10° 2.8xlo' 6 .3x10= 6 .8x10* 6 .3x10, 4 . 0x10 3  x  l  0  l  x  l  0  2 .9x10, 8. 6 x 1 0 ' 1 .8x10 ' 3 .3x10' 7 .3x10' 4 .4x10' 2 .7x10° 5 .2x10' 1 .1x10° 1 .9x10' 5 .1x10* 2 .7x10* 3 .7x10* 1 .1x10* 8 .0x10° 5 .0x10" 1 .6x10° 3 .6x10, 4 .7x10' 4 . 7x10  a : b: c : d:  see F i g u r e 1 some names i n f o r m a l area of lagoon drainage area ( i n part a f t e r M c D o n a l d and L e w i s , 1 9 7 3 , t a b l e I I ) e: t o t a l i n l e t w i d t h f : l a g o o n w i d t h m e a s u r e b* = A / ( L - + L-) T  L  [ ]: excludes  Table 2  L  p a s s a g e s between  the  2  2  1 2 3 4 5 6 7  of  (t» )  (m ) . c  ma p b c o d,e a name  barriers  I  D  lagoons  Yukon c o a s t .  / A  0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0  01 00 02 04 00 0 10 08 08 12 03 01 51 56 00 01 39 19 01 09  h: i: j: k: tn: n:  (n>) ( o )  (m)  (m)  A  —£B---B--  r 30 2 750 = 20 = 200 0 1500 0 5250 [ 1 3 7 0 ] 18750 6050 [2125! 750 525 [ 0] 5000 0 675 <40 1550 0 = 100 <70 570 [<300] °<3000 [ 0] = 2000 5250 <400 2020 4380 n 1500 o <10 120 • 350 <20 10500 7250 r  1200 860 190 270 750 5500 200 820 130 1500 1300 2800 630 310 280 4400 420 566 1800 2300  163  1.49  61  0.90  141  1.53  mean s u b a e r i a l b a r r i e r w i d t h a f t e r Lewis mean b e r m h e i g h t and Forbes, mean f o r e s h o r e s l o p e 1974 mean n e a r s h o r e s l o p e o p e n e d b e t w e e n 1970 a n d 1972 c l o s e d b e f o r e 1 9 7 2 ; i n 1 9 5 4 , g e o m e t r y was L =300m, L =1200m I  g  35  estuaries less  such as the Babbage.  than  0.01  The  ratio  t o a maximum o f 1.02;  A /A L  ranges  D  from  f o r t h e Babbage E s t u a r y ,  A /A =0.01. L  D  The  r a t i o of lagoon  k /(L- +L ) L  B  , has  1  measure  of  area  to  the dimension  mean  barrier-plus-inlet  o f l e n g t h and  coast-normal  lagoon  may  length,  be c o n s i d e r e d  width.  By  this  measure,  t h e Babbage E s t u a r y , W o r k b o a t P a s s a g e ( b e t w e e n H e r s c h e l and  the  mainland  shore),  Shingle Point spit, Point  C r i a  3')  Bay,  ria-3,  and  the  stand apart  and  the  Roland  from  Babbage  the  Lagoon,  s y s t e m , and Table but  2.  s i n c e been f i l l e d  former  thirteen  along  the  Roland  as  are  as  undoubtedly  Whale Bay,  systems the  Spring-Phillips  identified  rias  flooded  in  also,  Other lagoons,  appear t o have  (1973) have p r e s e n t e d  such  developed  coast.  These 2  2  for  and the  interest  F i g u r e 11.  the  the  Firth,  data  with  1100  km .  the  context,  are  Blow  rivers given  T h e r e i s a m a r k e d c o n t r a s t b e t w e e n t h e two  Deep C r e e k b e i n g l a r g e l y c o n f i n e d t o t h e c o a s t a l  a  Hypsometric  2  f o r Deep C r e e k , t h e two  present  Sea  with  2  Malcolm  the  include  t h e Babbage w i t h 5000 km ,  Babbage and in  morphometric  b a s i n s t h a t empty i n t o t h e B e a u f o r t  a r e a o f 6200 km ,  w i t h 3700 km ,  primary  Lewis  drainage  Yukon  drainage  curves  p o r t i o n of t h e  King  l a k e b a s i n s b r e a c h e d by c o a s t a l e r o s i o n .  M c D o n a l d and for  systems.  transgression,  w i t h sediment.  behind  e a s t of  Estuary are a l l v a l l e y  S p r i n g R i v e r v a l l e y was  a s t h o s e a t K i n g P o i n t and in  other  t h e o t h e r unnamed l a g o o n s  The  has  the southern  Island  t h e embayment  l a r g e submerged v a l l e y  submerged d u r i n g the l a t e - H o l o c e n e Backhouse  Bay,  a  plain,  of in  basins, while  36  O O  CM-i  AREA  (%)  FIGURE 11 H y p s o m e t r i c c u r v e s f o r Babbage R i v e r and Deep Creek d r a i n a g e b a s i n s ( m o d i f i e d a f t e r McDonald and L e w i s , 1 9 7 3 , f i g u r e 6 ) .  37  t h e Babbage and Mountains.  As  particularly  a result,  snowmelt  significantly 3.1.1  t r i b u t a r i e s d r a i n p a r t s of t h e B a r n and  runoff,  (McDonald  and  may  be  Lewis,  f r o m t h e two b a s i n s , expected  1973,  to  p.22;  differ  c f . section  below). Accumulations  considerably Malcolm  in  of  and F i r t h and  c h a r a c t e r i z e d by tidal  latter  deltaic  size  by b r a i d e d c h a n n e l  and  r u n o f f response  British  and  morphology.  Major  distributary  L e w i s , 1973; changes  The  the  coast  in  The  dominated  the d e l t a s  l a r g e s t d e l t a s of  t h e Babbage ( M c C l o y ,  L e w i s and  Forbes,  are  p h y s i c a l environment  produced  1970,  the  1971;  1974).  c o a s t r e g i o n have o c c u r r e d d u r i n g l a t e Q u a t e r n a r y r a p i d c o a s t a l e r o s i o n has  the  f l o o d p l a i n s w i t h numerous l a k e s  channels.  the  vary  f a n d e l t a s of  at other l o c a t i o n s ,  supratidal  t y p e a r e t h e Blow and  M c D o n a l d and  at  i n e a s t e r n C l a r e n c e Lagoon a r e  networks;  low  sediment  o f t h e Yukon time;  s u b s t a n t i a l changes  indeed, in  the  c o a s t a l c o n f i g u r a t i o n d u r i n g t h e p a s t c e n t u r y and  a half, since  the  The  reconnaissance  geomorphology,  long-term  e s t u a r i n e systems, be  understood  by  in  and  Franklin trends  in  (1828). the  behaviour  the n a t u r e of sediment  existing of  s t o r a g e , can  the c o n t e x t of t h e s e changes, which a r e  s u b j e c t of the f o l l o w i n g  section.  the only the  38  2.1.2  LATE-QUATERNARY  Rapid the by  erosional  Yukon  coast  G. Mizerovsky  as  much  during  as  at  the  several  the  lagoon,  metres  part  1973). the  Figure  V ) ,  12.  recession m a "  1  the  west  of  termed  of  coast  v i c i n i t y  the  suggests  of  as  for  of  the  tentative  Kay  the  Babbage  ice coast  as  of as  Island  Buckland  150  that  of  is  years  as  major changes  time  end of  Kay most  Point rapidly  (McDonald  map,  taking of  into  latitude  (Franklin,  shoreline  1828,  plotted  extraordinary i n  planform have  and  excess and  been  in mean of  dynamic r a d i c a l l y  ago.  pre-Wisconsin  the  (Hughes,  may  a  amounting  at  the  spit  an  coastal  western  retreat  Point  discussed  10B)  the  that  Kay  substantial  promontory the  Estuary  or  1826 y i e l d s  Point  earlyfar  at  present  1826  out  long-term  F r a n k l i n ' s  the  carried  at  and .his observation of  indicates  Herschel  the  the  interpretation  recently  Yukon  the  for  Kay Point  at  in  year  of  revealed  (Figure  coastal  1826.  bathymetry  Continental along  in  It  environment  per  rapid  has  much  (1963b)  1905,  Point  recession  survey  This  .  King  work  disappearance  since  present  rate  different  Point  the  Mackay  v i r t u a l  at  along  occurred  evidence  An i n t e r p r e t a t i o n  (69°18'45"N) appendix  the  1973)  recession  1952-1970.  of  occurring  and Lewis,  and remarkably  retreating  is  Photogrammetric  coastal  interval  F r a n k l i n ' s  account  of  Sabine  same  to  40  m  including  promontory  Lewis,  present.  and geomorphological  recession,  since  at  interval  h i s t o r i c a l  during  transgression  (McDonald  88  the  PALAEOGEOGRAPHY  present  1972).  G l a c i a t i o n . by  F i r t h  This  Rampton  age  flowed  River  advance (in  west  outlet, has  press).  been It  FIGURE 12 Tentative late-Wisconsinan and 1826 p a l a e o g e o g r a p h y b e t w e e n Kay P o i n t and H e r s c h e l I s l a n d ( i n part a f t e r F r a n k l i n , 1826).  40  caused and  widespread deformation  of p r e - e x i s t i n g f r o z e n  a s s o c i a t e d g r o u n d i c e ( M a c k a y , 1959;  and  may  have  material  created  now  forming  Herschel  1972;  a  Island  (Mackay,  1972)  1959).  t o t h e Yukon c o a s t ,  possible late-Wisconsinan  M a c k a y e t a l . , 1 9 7 2 ) , i s now  southern  al.,  B a s i n , e m p l a c i n g much o f  Herschel  prominent moraine r i d g e p a r a l l e l considered  Mackay e t  sediments  ice limit  considered  m a r g i n of a m a j o r s t i l l s t a n d  the A  previously  ( c f . Hughes,  to represent  the  or readvance, termed  the  S a b i n e p h a s e , of t h e B u c k l a n d G l a c i a t i o n (Rampton,  in  press).  The  the  Babbage  major  valley  Delta, parallel  of H e r s c h e l  scour  and  Mackay,  occupied  t o t h e Yukon c o a s t  axis  in  now  B a s i n , may  part  to  by Deep C r e e k and and  distal  of  the  late-Buckland  late-Wisconsinan  delta  (J.R. Mackay,  Rampton, i n p r e s s ) .  This  upper i c e s u r f a c e  press,  figure  attained  was  18).  with  directly  years  i n the  B.P.  a f f e c t e d by  than  present  1980,  sea is  (cf.  seaward of  sea  the  (Rampton,  between The  13500 Yukon  the and the  and coast  time.  marine t r a n s g r e s s i o n to  During  in  i c e i s b e l i e v e d t o have  g l a c i a t i o n at that  fragmentary  1979;  i n t e r s e c t i o n of  level  region  in  the  communication,  ( P r e s t , 1969).  level  pp.. 7 6 - 7 7 ) .  i n the v i c i n i t y  i s b a s e d on  Late-Wisconsinan  Mackenzie D e l t a region Forbes,  glacial  runoff  g l a c i a t i o n advanced  present  Evidence for post-Buckland higher  proglacial  personal  limit  i t s maximum e x t e n t  radiocarbon  not  major  be a t t r i b u t a b l e i n p a r t t o  through the Mackenzie D e l t a t o a l i m i t  14000  the  1959).  Ice  the  aligned with  northern  levels  Yukon  inconclusive  and (see  late-Wisconsinan  41  g l a c i a t i o n , on the dropped  to  a  other  minimum  hand, some  sea  60-80 m  l e v e l ' appears  to  have  below the present  level  (Forbes, 1980), l e a d i n g to c r e a t i o n of a lake (here Lake  Herschel)  (Figure 12).  at  The  about  -15±1  Babbage  River  m e l e v a t i o n i n H e r s c h e l Basin may  Herschel  f o r 15000 years or more.  southeast  end  have  drained  of the Lake H e r s c h e l b a s i n (Figures 12 and formed by  R i v e r and t r i b u t a r i e s ,  including Spring River.  Available  data  and  sediments  associated  p o s t g l a c i a l sea l e v e l s i n the southern  the  i n d e t a i l by Forbes  Holocene  appears  transgression  that  late-Wisconsinan area  to  limited i c e may  (1980). is  from  ambiguities  the  Information  extremely  Babbage  have  r e l e v a n t to  depression  have o c c u r r e d i n the  Mackenzie  coast  have  evidence,  also,  There i s some  strong  few  therefore  collective  the mid-  attributable past  E . Reimnitz,  (Faas, 1966;  throughout  Despite  at i n d i v i d u a l s i t e s , data a v a i l a b l e from the Yukon  pp.88-94; Mackay and Stager, 1966), and  provide  Delta  forebulge may  (Appendix A.13), from the outer Mackenzie D e l t a  1963a,  It  beneath  of recent and perhaps c o n t i n u i n g r e g i o n a l submergence.  coast  to  been  fragmentary.  and to the southeast, while a marginal  ambiguities  13) i s  relating  Beaufort Sea  isostatic  e x i s t e d to the north and west.  Lake  An e x t e n s i v e t e r r a c e at the  i n t e r p r e t e d as a d e l t a  discussed  designated  to  point  support  for  rising  to l a t e Holocene, i n excess  years  from the Alaska  p e r s o n a l communication,  global variation  thousand  (Mackay,  (cf.  of  1978),  sea  level  the  trend  i n g l a c i a l volume d u r i n g the Walcott,  to a hypothesis of broad  1975).  The  data  r e g i o n a l submergence  42  FIGURE 13 Profile along axis of Babbage Valley and Herschel Basin, showing hypothesized l a t e - W i s c o n s i n a n water l e v e l i n Lake Herschel (broken line) and p r e s e n t y a l l e y - a x i s s l o p e s o f Babbage R i v e r a n d t r i b u t a r i e s .  43  on  the  Yukon c o a s t  The should best.  tentative be  sea  regarded  I t conforms  involving following  some  years  Island have 1000  B.P.  been years  possibility  as ago; of  the thaw  outline  the  1980).  On  be  in  suggest  area, this  the  level  data  are  somewhat the  guess  at  the  marginal by  Basin date  in this  ambiguous,  Delta  rapid  beginning  datum as  sites.  sequence  a  Babbage D e l t a and  below present  at  as  tentative  1 m  14  Mackenzie  in Herschel  sea  Figure  educated  accompanied  as  subsidence  in  plausible  basis,  a  the that  an  subsidence  assigned from  as  to a  transgression  Dates  much  being  f o l l o w e d by  may  A.13)  illustrated  rebound  through  marine  (Appendix  time  isostatic  Babbage R i v e r v a l l e y 6000  history  f o r the  (Forbes,  Holocene  Holocene.  in general  moved  sedimentation  the  level  deglaciation,  forebulge  the  during  and  of  of the  about  Herschel area  may  recently  as  due  to  the  44  20  T  10  03  0-  D 2  R-|3  D3 •  2  D 2  -10--  4 \ -20--  REGION 1 southern Banks Island  -I z  - 3 0 - -  3 Yukon coast  o  5  2 Mackenzie Delta  -40+-  4 Alaska coast  > ORIGINAL POSITION  LJ  -50  -60--  LTD above datum I H at datum below datum  -70--  1  2  3  4  10  11  12  13  14  15  TIME B.P. (xlOOO years)  FIGURE 14  Data base and t e n t a t i v e history of late Wisconsinan and Holocene sea l e v e l s i n Mackenzie D e l t a and on t h e Yukon c o a s t (after F o r b e s , 1980).  45  2.2 ATMOSPHERIC 2.2.1  ENVIRONMENT  CONTEMPORARY CLIMATE The  present  regional  climate  o f t h e n o r t h e r n Yukon a n d  s o u t h e r n B e a u f o r t Sea i s s t r o n g l y s e a s o n a l , w i t h s e v e r e w i n t e r s and c o o l  summers, m a r k e d by a p r o n o u n c e d m e s o s c a l e  g r a d i e n t normal t o the c o a s t . at  Shingle  Point  10.7°C i n J u l y The  The m o n t h l y mean a i r t e m p e r a t u r e  (68°57'N, 137°13'W) r a n g e s f r o m a maximum o f  t o a minimum o f -27.7°C i n F e b r u a r y ( F i g u r e 1 5 ) .  t e m p e r a t u r e r e g i m e a t Komakuk B e a c h ,  o f Kay P o i n t , July,  due  coast  west  in  personal  temperatures  in  p a r t t o t h e p e r s i s t e n c e of sea i c e c l o s e t o t h e  of  Komakuk  some 75 km t o t h e w e s t  i s s i m i l a r , w i t h somewhat c o o l e r  Herschel  Island.  The  t e m p e r a t u r e i s -10.4°C a t S h i n g l e P o i n t at  temperature  Beach  (R.E. Wahl,  communication,  mean  (1959-1973)  A.E.S.  1978);  annual  screen  a n d -11.6°C  Yukon Weather  this  compares  Office, with  a  c o n t e m p o r a r y mean a n n u a l n e a r - s u r f a c e g r o u n d t e m p e r a t u r e on t h e Yukon C o a s t a l P l a i n pp.173-174).  o f a p p r o x i m a t e l y -8.5±1.5°C ( M a c k a y ,  Equilibrium  ground  w i t h v a r y i n g snow c o n d i t i o n s  temperature  varies  ( J u d g e , 1973; Mackay  and  1975b, locally MacKay,  1974), w i t h p r o x i m i t y t o major water b o d i e s , and of c o u r s e w i t h depth. region,  Mean a n n u a l p r e c i p i t a t i o n amounting  t o 188 mm  S h i n g l e P o i n t , 127 mm 206 mm  ( o f w h i c h 76 mm  (51 mm a s snow)  at  f a l l s a s snow) a t  Komakuk  Beach,  and  (97 mm a s snow) a t O l d Crow, s o u t h o f t h e m o u n t a i n s .  In w i n t e r , the r e g i o n  i s d o m i n a t e d by a dome o f r e l a t i v e l y  c o l d and s t a b l e c o n t i n e n t a l A r c t i c frontal  t o t a l s a r e low t h r o u g h o u t t h e  lows  around  ( c A ) a i r , w h i c h d i v e r t s most  i t s periphery  (Burns, 1973, pp.18-19).  46  FIGURE 15 M o n t h l y t e m p e r a t u r e and p r e c i p i t a t i o n d a t a f o r Komakuk B e a c h a n d S h i n g l e P o i n t , on t h e Y u k o n coast, and f o r O l d Crow, south of the mountains (data courtesy Atmospheric Environment S e r v i c e ) .  47  Anomalous warming t r e n d s a s s o c i a t e d w i t h o c c a s i o n a l  penetration  of l o w - p r e s s u r e c e n t r e s i n t o t h e r e g i o n may p r o d u c e  temperature  e x c u r s i o n s a s g r e a t a s +30K (Wiseman a n d S h o r t , in  some  cases,  these  events  t e m p e r a t u r e s a l o n g t h e Yukon  culminate  coast  and  1976,  in  may  p.236);  positive a i r  generate  winter  storm surges. The  transition  from  winter  importance because of t h e major sediment  transport  radiation  i n p u t s , changes  northward activity  retreat  process,  of  by  cool  and  The  Yukon  1966).  Low  pressure  systems  region  along  the  Arctic  (Reed  wettest  months  Precipitation  of  the  also arises  largely  snow  year  ablation,  Yukon  cyclonic coast  during  the  ice-free.  is  (mA) a i r , w h i l e  (Bryson, frontal  generate  and  zone  Kunkel, I960; eastward  1966). lies  Bryson,  through  the  much o f t h e summer  August,  which  Cyclonic are the  ( B u r n s , 1 9 7 3 , p . 1 8 ; F i g u r e 15)..  from i n s t a b i l i t y  of  mA  a i r moving  warmer c o a s t a l p l a i n a n d a d j a c e n t m o u n t a i n s ,  i s heated from below.  common  increasing  (Hare, 1969, p.188; B u r n s , 1973, p . 1 9 ) .  i s a t a maximum i n J u l y  it  and  passing  front  activity  i n the  a i r p e n e t r a t e s t o t h e c o a s t , on  of t h e A r c t i c / P a c i f i c  northern  particular  frequent  moist maritime A r c t i c  the  the  more  I n summer, t h e  across  across  to  20 p e r c e n t o f t h e t i m e i n J u l y  modal J u l y p o s i t i o n  precipitation  due  a i r , and  r e l a t i v e l y warm a n d d r y P a c i f i c a v e r a g e , about  of  r o l e o f snowmelt r u n o f f  albedo  ( B u r n s , 1973, p.16).  dominated  summer,  i s m a r k e d by r a p i d l y  in  cA  to  where  E x t e n s i v e low c l o u d i n e s s and f o g a r e  summer  months,  when  coastal  waters are  48  Precipitation the  1974-1976  summer  investigations presented  was m e a s u r e d a t Kay P o i n t seasons, i n support  described  below.  i n T a b l e 3.  years, p a r t i c u l a r l y  2.03 mm p l u s n i n e  low  runoff  rates  i n 1974 a n d t h e  of  t h e month;  ( t h i s r e s u l t e d i n extremely  i n t h e Babbage  River  in  data  camp  f o r a s i n g l e summer s e a s o n  at  Sam L a k e  These d a t a 1978)  near-surface season. Island  some  by  Precipitation  during data  observations Beach,  Territory,  (Canada,  personal  communication,  an  unusually  cool  series, a t Kay  Atmospheric  Environment  Herschel  have  Service,  complete p i c t u r e of geographic  beginning  Point,  a n d wet  also c o l l e c t e d a t Herschel  i s therefore a v a i l a b l e f o r that season.  precipitation  There a r e  of the s p a t i a l v a r i a b i l i t y of  were  M o n t h l y R e c o r d ) a n d an u n u s u a l l y variability  coast  (1974) a r e a v a i l a b l e f r o m a  R.E. W a h l ,  indication  conditions  i n 1974  Yukon  the  basin  (68°25'N, 138°37'W; P e a r s o n a n d Nagy, 1 9 7 6 ) .  (furnished  provide  at  o f t h e mean b a s i n p r e c i p i t a t i o n .  s t a t i o n s i n the mountains of t h e northern  but  July:  3.1.1).  (Figure 1 1 ) , i t i s improbable that p r e c i p i t a t i o n  no  late  t h e s i z e a n d hypsometry o f t h e Babbage R i v e r  representative  the  16 J u n e t o 15 J u l y amounted t o  trace events  Q<0.2 mm/day; s e e s e c t i o n  is  are  The g r e a t e r p a r t o f J u l y  near t h e end  f o r t h e 30-day i n t e r v a l  Given  statistics  the high J u l y p r e c i p i t a t i o n  only  of  Note t h e s t r i k i n g d i f f e r e n c e s between  p r e c i p i t a t i o n occurred  total  parts  of the hydrological  Summary  l a r g e number o f t r a c e e v e n t s i n 1 9 7 5 . 1975  during  with been  the  Cumulative  first  computed  date  of  f o r Komakuk  I s l a n d , Kay P o i n t , a n d S h i n g l e P o i n t , t o y i e l d  49 TABLE  3  Monthly  precipitation  month/^ear  proportion of r e c o r d missing  data,  Kay  Point.  number observed of trace p_r e c i p_i t a t i o n _ e v e n t s  %  estimated total total snow EE££iEi£££i£!!_"£££E mm  mm  >18. 1 >22 . 7  3 3  July Aug  1974 1974  32 32  ( 1 7 . 74) ( 2 2 . 34)  J une July Aug  1975 1975 1975  40 0 0  (  2.0 3 ) 7 .07 25 . 47  4 14 17  June July Aug Sept  1976 1976 1976 1976  0 0 0 67  29 . 76 8. 74 24 . 10 ( 3.0 0 )  6 1 3 1  0 0  2 .5 8. 8 27 .6  >0 0 =1  30 .5 8 .9 24 .5 > 3.1  T  >  .  mm  4 0 >0  50  an  east-west transect along  t h e c o a s t , and  Crow, t o y i e l d a n o r t h - s o u t h  f o r Sam  transect across  s e r i e s a r e p l o t t e d i n F i g u r e 16.  In  1974,  totals  on  the  were  very  much  higher  mountains than along  the c o a s t .  data, p r e c i p i t a t i o n  totals  consistent  along  Apart  appear  the c o a s t , being  precipitation  may  Old  the mountains;  the  the  precipitation  south  flank  of  from the H e r s c h e l  to  have  been  and  provide  the  Island  relatively  somewhat h i g h e r  a t S h i n g l e P o i n t ; t h i s p a t t e r n h e l d f o r 1975 appears that Shingle Point data  L a k e and  i n the  1976  east  also.  the best  It  available  estimates  of  i n t h e Deep C r e e k b a s i n but  relatively  u n r e l i a b l e g u i d e t o c o n d i t i o n s i n the upper  are  a  Babbage  River. Much o f t h e  important  systems of t h e Yukon c o a s t in  July  and  pressure  August.  a t Kay  F i g u r e 17.  Point  The  during  The  summer is  1976  The  is  essentially  poorly,  in  monotonic, in  5  the  d e f i n e d s t r u c t u r e a t T=l breeze  g r e a t e s t p a r t of the v a r i a n c e  hourly  presented  f " , approximately,  t h e d e v e l o p m e n t o f a weak l a n d - s e a  summer. lower  v a r i a n c e d e n s i t y spectrum of  spectrum  0.5<T<2.5 d a y s .  in estuarine  i s associated with cyclonic activity  The  v a r i a n c e d e n s i t y v a r y i n g as  reflect  synoptic-scale variance  clearly  with range  day  may  pattern  in  resides at  frequencies. Hourly  during  the  obtained tundra  mean w i n d v e l o c i t i e s were 1974-1976  approximately  surface.  (mid-July  to  field  recorded  seasons.  16 m a b o v e s e a  The level,  Frequency d i s t r i b u t i o n s early  September)  of .1975  at  Point  m e a s u r e m e n t s were 10 m  f o r the and  Kay  above  the  summer s e a s o n s  1976  are  shown i n  51  FIGURE  16  Cumulative p r e c i p i t a t i o n at stations in n o r t h e r n Y u k o n T e r r i t o r y , summer 1974.  the  < > 1 Cf  10" FREQUENCY  ID-  (cycles/hrO  FIGURE 17 Variance density spectrum o f . hourly atmospheric pressure a t Ray P o i n t , summer 1976; t h e 90% c o n f i d e n c e i n t e r v a l , assuming a chi-square d i s t r i b u t i o n with 10 d e g r e e s o f freedom, i s g i v e n a t upper r i g h t .  53 N  1975  w  s N  1976  FIGURE  18  Relative frequencies (m/s) by direction, r e c o r d s , Kay P o i n t .  of hourly wind 1975 a n d .1976  speed summer  54  F i g u r e 18.  The  Kay  Point data  winds from the northwest secondary  maximum  coast  differ  may  (1973, two  particularly  in  i n these of  the  two  pointed greater the  seasons,  southeast  significantly  p . 1 7 6 ) has  to four times  trough  out  i n d i c a t e p r e v a i l i n g and  out  from  with  i n 1976. winds  a  strong  Winds a t  offshore;  the  Burns  t h a t w i n d s o v e r t h e w a t e r may  than  at  nearby  coastal  be  stations,  p r e s e n c e of a s u r f a c e c o l d f r o n t o r of  a  o f warm a i r a l o f t .  Variance  density  northwesterly ( F i g u r e 19)  spectra  components  of  of  northeasterly  wind  stress  show maxima a t a p p r o x i m a t e l y  T=5  land-sea  or p e r i o d s synoptic  breeze e f f e c t . corresponding  range  distribution microscale  of  (especially  tidal  Synoptic-scale  southern  ( s y n o p t i c - and  ascribed  processes,  Sea.  is in  of  peaks  in  microtidal  settings  to  the  relative  mesoscale,  and  system,  seasonal-scale)  major  particular,  the  frequencies  a s s o c i a t e d w i t h d i u r n a l or s h o r t e r effects)  Point  while  here than the  macroscale,  and  Kay  I n an a n a l y s i s o f t h e e s t u a r i n e  importance i n  Beaufort  density  concern  among  between m e s o s c a l e events  considerable  variance  less  variance  and  day,  However, the p a r t i c u l a r to  of  processes.  the p a r t i t i o n events  are  at  days,  n o r t h e a s t e r l y component e x h i b i t s a peak a t T=l a  dominant  periods  interest. may such  assume as  the  FIGURE  19  V a r i a n c e d e n s i t y s p e c t r a f o r n o r t h e a s t e r l y and northwesterly components of hourly wind s t r e s s , Kay P o i n t , 1976.  56  2.2.2  LOW-FREQUENCY When  observed  V A R I A B I L I T Y OF CLIMATE  a n a t u r a l h y d r o l o g i c a l o r s e d i m e n t o l o g i c a l system i s over a p e r i o d of a  conclusions  may  be  few  years  seriously  biased  undetected  trends i n input variables  parameters  of t h e system,  level  and  coastal  Furthermore, between  years,  presence  of  of  (section may  be  sea  2.1.2). detected  n a t u r e and magnitude of t h e low-frequency  and  ocean-atmosphere  above  differences  v a r i a n c e may n o t be r e a d i l y d e t e r m i n e d . year-to-year  the  and  ( s e e below) o r even i n t h e  described  significant  the  by  hypotheses  a s e x e m p l i f i e d by t h e t r e n d s  retreat  while  only,  longer-term  system,  as  c e n t r a l Yukon c o a s t , a r e o f  For these reasons, the  variability  they  affect  great  of  the  conditions  on t h e  relevance  to  the  present  study. Walsh  and  Johnson  v a r i a t i o n s of A r c t i c  (1979)  have  i c e extent  identified  exceeding  five  year-to-year degrees  of  l a t i t u d e a t most l o n g i t u d e s a n d a s i g n i f i c a n t p o s i t i v e t r e n d o f total  i c e cover  over  the  past  few  pp.35-45) p r e s e n t e d a c l a s s i f i c a t i o n in  the  southern  Beaufort  Sea  the  o v e r t h e A r c t i c Ocean ( c f .  Other  models have  with  mean  long-term  o f summer  and r e l a t e d  m o d e l of. i c e c i r c u l a t i o n d r i v e n by pressure  been  summer  periodicities  Classifications interpretation  investigated,  temperatures in  years.  at  early  Mar