Towards a national-scale assessment of the subaqueous mass movement hazard in Canada

Abstract

Characterized by an active margin to the west, passive margins to the east and north, and numerous fjords and estuaries, the seafloor of Canada is prone to subaqueous landslides. The Geological Survey of Canada (GSC) facilitates government response in times of crisis by providing timely and concise information to Canadians, and informs the strategies to address natural hazards. Thus, the GSC is conducting a national assessment of the subaqueous landslide hazard. This paper reviews dozens of major subaqueous mass movement deposits with an emphasis on recent publications and summarizes the attempt to produce a national database. The types range from ephemeral turbidity current deposits to very large deposits (>100 km3). To date, 1266 deposits are identified with many more expected as mapping progresses. This work is important as it will feed into the larger national tsunami strategy, and is a step forward for the national government to manage the risk. Canada is among the first countries to enter its entire database using the consistent morphometric characterization recommended by members of the UNESCO IGCP-640 (S4SLIDE) Community.

Numerical modeling of a potential landslide-generated tsunami in the southern Strait of Georgia

“…The hazard of landslide tsunamis on the west coast of Canada remains poorly understood; the historical and geological record of slope failures is incomplete, as much of the seafloor remains to be mapped or studied in detail (Lintern et al 2020). Only a few landslide tsunami modeling studies have been completed for the region, including the 1975 submarine failure in Kitimat Arm (Skvortsov and Bornhold 2007), the sixteenth-century subaerial failure in Knight Inlet (Bornhold et al 2007), and potential submarine failures of the Fraser delta front (Dunbar and Harper 1993;Rabinovich et al 2003), and offshore Texada Island (Rabinovich et al 2003).…”