CGRG Bibliography of Canadian Geomorphology
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Author : Campbell, C.; Duchesne, M.; and Bolduc, A.
Date : 2008.
Title : Geomorphological and geophysical evidence of Holocene seafloor instability on the southern slope of the Lower St. Lawrence Estuary, Québec.
Publication : 4th Canadian Conference on Geohazards: From Cause to Management. May 20-24, 2008. University Laval, Quebec City, Quebec.
Issue :
Page(s) :
Abstract
New seafloor mapping data combined with data collected in the 1980s reveal several instability features on the seabed along the southern slope of the Lower St. Lawrence Estuary, Québec. The datasets consist of multibeam bathymetry, seafloor samples, and very high resolution seismic reflection profiles. Instability features range from lateral spreading and possible liquefaction to rotational slumps, debris flows and blocky submarine landslides. Age estimates for instability events range from 7 ka to recent. There are a number of similarities among the areas examined. Specifically, failure horizons are confined to the contact between ice-distal and paraglacial sediments, headscarps are associated with changes in underlying bedrock gradient, and failure zones lie seaward of major rivers. A number of factors may contribute to the observed instability including seismicity, high sedimentation rates, sub-surface gas, and sea-level history.
Bibliography of Canadian Geomorphology