CGRG Bibliography of Canadian Geomorphology
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Author : Davidson-Arnott, R.G.D.
Date : 1999
Title : Nearshore erosion on cohesive coasts in the Great Lakes.
Publication : 1999 Canadian Coastal Conference. Royal Roads University, Victoria, British Columbia, May 19-22, 1999.
Issue :
Page(s) :
Abstract
It is now recognized that nearshore erosion is an important control on recession and profile evolution of cohesive bluff shorelines. This paper presents the results of a three-year study of underwater erosion of till at three sites on the Great Lakes, one on Lake Ontario and two on Lake Huron. Measurements of erosion underwater were made along three profiles at each site using a micro erosion meter. At the same time a number of characteristics of the nearshore profile were measured, including thickness of surficial sediment, presence of lag deposits, shear strength of the till surface and variations in shear strength and moisture content with depth in the till. Results show that rates of erosion in the relatively dense, stoney St Joseph’s Till which forms the substrate of the Lake Huron shoreline, are considerably lower than those measured on the Lake Ontario shoreline in Halton Till. The lower rates on Lake Huron reflect a generally thicker overburden and protection offered by accumulation of a cobble lag as well as by reduced susceptibility to softening of the till surface during periods of low wave activity in the St. Joseph Till compared to the halton Till. A generalized model of the controls on underwater erosion of the cohesive profile has been developed from these measurements.
Bibliography of Canadian Geomorphology