CGRG Bibliography of Canadian Geomorphology
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Author : Fraser, C.; Bernatchez, Y.; Jolivet, Y.; Friesinger, S.; and Dugas,S.
Date : 2009.
Title : Influence of the climate on coastal erosion in temperate regions; Gulf of St. Lawrence, Quebec, Canada.
Publication : MOCA-09, Our Warming Planet. Joint Assembly of the IAMAS, IAPSO and IACS. July 19-29, 2009. Montreal, Quebec.
Issue :
Page(s) :
Abstract
An analysis of the relationship between various climate variables and coastal erosion rates measured from 1931 to 2006 in the Gulf of St-Lawrence (GSL) indicates that storminess and winter conditions are the dominant factors controlling coastal dynamics. The three test sites chosen for this study are Magdalen Islands, Sept-Îles and Percé. The study shows that several beaches of the Sept-Îles area were exposed to acute erosion during the 1965-79 and the 1996-2006 periods. The systematic comparison of climate factors with high erosion rates indicates that more waves from south-east induced by storminess and a shorter ice season due to mild winters that open the coastline to winter waves were the main causes of this erosion. This was identified as the major cause of the decrease of beaches width and the increase of coastal retreat. At other sites, such as Magdalen Island and Percé, winter storminess and the total wave energy reaching the coastline also increased during some periods, but other winter processes also contribute to raising the erosion rates of soft cliff made of red sandstone and poorly sorted conglomerates. The frost and thaw cycles, winter rain events and winter mild spells prove to be the main cause of increased erosion on a large part of these shorelines. These winter processes also affect the silt-clay banks of the Quebec north shore. This new information leads to a better assessment of the impact of climate change on cold temperate coastal region.
Bibliography of Canadian Geomorphology