Canadian west coast fjords and inlets of the NE Pacific Ocean as depositional archives

Abstract

AbstractThe west coast of Canada is one of the major fjord coastlines of the world, hosting about 150 fjords which are locally known as inlets. Much of the coastline remains remote without extensive research, and this paper summarizes what is known of the Canadian west coast fjord environments. Two fjord regimes are recognized along the British Columbia coastline. Mainland fjords drain high mountains and ice fields with sediment input from snowmelt and glacier runoff in spring and summer. By contrast, the inlets on Vancouver Island are in a milder marine climate, and sediment input occurs mostly during heavy rains of autumn and winter. Due to unique oceanographic conditions and shallow sills at the mouth of some Vancouver Island inlets, anoxic bottom waters exist which allow the preservation of annually laminated sediments. Studies of these annually laminated sediment archives over the past decade, including two international drill ship investigations, have characterized the deglacial, sea-level and palaeoenvironmental history of the British Columbia coastal area. These coastal depositional archives have also advanced our knowledge of the cyclical nature of the NE Pacific ocean and climate system, as well as given evidence of infrequent, yet significant abrupt changes that characterize it.