CGRG Bibliography of Canadian Geomorphology
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Author : Crawford, W.R.; and Thomson, R.E.
Date : 1999
Title : Sea level rise in British Columbia.
Publication : 1999 Canadian Coastal Conference. Royal Roads University, Victoria, British Columbia, May 19-22, 1999.
Issue :
Page(s) :
Abstract
Although global climate change can be expected to have a profound influence on long term sea level, it is only one of several factors affecting coastal sea level variations. Accurate estimates of present and future sea level change also require a thorough understanding of regional phenomena such as glacio-isostatic rebound, plate tectonics, hydrological processes and the variability of prevailing atmospheric pressure and wind systems. Global sea level is rising between 1 and 2 millimeters per year due to thermal expansion of the ocean (steric processes) and ocean volume increases resulting from the melting of land-based glaciers and ice sheets (eustatic processes). Within British Columbia there are major differences in the rates of sea level rise at the southern and northern sectors of the coast due to uplift along the suthern coast caused by the frictionally locked subduction plate under Vancouver Island. Major differences exist in the rates of sea level rise along the inner and outer coastal waters of British Columbia as a result of spatial differences in the glacio-isostatic rebound. Expected sea level rise rates for British Columbia range from –1 to +2 mm/yr on the south coast to –1 to +6 mm/yr on the north coast. However, regions where sea level is presently falling can expect a sudden rise accompanying an earthquake along the Cascadia Subduction Zone. An increase in the strength of the Aleutian low pressure system in the Gulf of Alaska, and increased advection of warm water along the west coast between California and British Columbia both raise sea levels during El Nino. Sea levels were 200 to 300 mm higher than normal during the entire El Nino winters of 1982/83 and 1997/98. Examination of previous records at Point Atkinson reveals that six of the eight highest sea levels ever observed were during El Nino winters. If global sea level rise does lead to increased coastal erosion, this erosion will likely be most severe in British Columbia during El Nino winters.
Bibliography of Canadian Geomorphology