UBC Theses and Dissertations
Seasonal and secular variations of sea level with special reference to the Canadian Pacific Coast Siebenhuener, Hajo Fritz Wilhelm
In the first part of this thesis definitions of sea level are given and causes and effects of its seasonal and secular variations are briefly discussed. The second part deals with the numerical determination of these changes on the coast of British Columbia. Using raw tidal data in the form of monthly means of sea level, seasonal variations are determined as annual oscillations with mean amplitudes between 5 and 12 cm for seven stations on the B.C. coast. The investigation of secular variations is based on (raw) annual means of sea level. These variations are essentially represented by linear trends which are statistically significant at the stations VICTORIA, VANCOUVER, POINT ATKINSON and PRINCE RUPERT, where they indicate submergence. Assuming an eustatic rise of sea level at the rate of 1.0 mm/yr, the influence of land movement on submergence is estimated. For VICTORIA, a probable land uplift since 1909 and for VANCOUVER, POINT ATKINSON and PRINCE RUPERT a definite land subsidence since about 1943 is found. The rates of land subsidence range between 1 and 2 mm/yr.
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