The rock coast of Canada

Abstract

Canada's coasts, which are primarily rocky, extend along three oceans and four Great Lakes. Many processes operate here in the same way as in other places, but glacio-isostatic uplift, coastal permafrost and ground and sea ice assume particular importance in the Canadian context. Only small amounts of wave erosion have occurred on the very resistant rocks of the Canadian Shield, where rapid changes in relative sea-level have limited the time that marine processes operated at any particular level. The Pacific coast and most of the northern Atlantic coast consist of fiords and most steep coastal slopes have been cut by glaciers. Marine processes have been more effective on weaker substrates in southern Canada, where there are a variety of stacks, arches, wave-eroded cliffs and wide shore platforms. Most work has been conducted on the southern Great Lakes, where rapid erosion and recession of glacial clay cliffs threaten human populations and infrastructure, and on the subhorizontal and sloping shore platforms of Atlantic Canada and eastern Québec.