Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ouellet, M. Search for Related Content GeoRef GeoRef Citation

Lake sediments and Holocene seismic hazard assessment within the St. Lawrence Valley, Québec

¹ INRS-Freshwater Center, University of Québec, Ste-Foy, Québec G1V 4C7, Canada

Seismoacoustic profiling of 34 lacustrine basins within the St. Lawrence Valley in southern Québec shows the presence of faulting, convolution, diapirs, and gravitational slumping beneath, within, and at the surface of the Holocene deep-water–sediment zone. In small, deep lakes in the highlands of the Charlevoix-Tadoussac region, a thin (2–6 m) Holocene organic sedimentary unit, which directly overlies over a seismo-opaque substratum, exhibits considerable deformation. These subaquatic sediment disruptions are exclusively restricted to lakes located within a radius of about 100 km of the well-known Charlevoix seismic zone.

According to the present seismicity of the region and the spatial distribution of the slump frequency, the minimal-triggering threshold for earthquakes was found to be as low as 0.17 g. These results indicate that the Charlevoix seismic zone has occupied the same area throughout at least the Holocene, and it appears that no major seismic shock has occurred over the past several thousand years outside of the zone.

This article has been cited by other articles:

				S. L. Brown, P. R. Bierman, A. Lini, and J. Southon 10 000 yr record of extreme hydrologic events Geology, April 1, 2000; 28(4): 335 - 338. [Abstract] [Full Text] [PDF]