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TitleTsunami hazard assessment of Canada
AuthorLeonard, L J; Rogers, G C; Mazzotti, S
SourceNatural Hazards vol. 70, no. 1, 2013 p. 237-274,
Alt SeriesEarth Sciences Sector, Contribution Series 20130130
Mediapaper; on-line; digital
File formatpdf
ProvinceWestern offshore region; Eastern offshore region; Northern offshore region; British Columbia; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS25; 26; 27; 92B; 92C; 92D; 92E; 92F; 92G; 92K; 92L; 92M; 92N; 103; 102I; 102P; 104B; 104C; 104D; 104E; 104F; 104G; 104K; 104L; 104M; 114; 1; 2; 10; 11; 12; 20; 21; 22; 35; 36; 37; 38; 39; 45; 46; 47; 48; 49; 57; 58; 59; 67; 68; 69; 77; 78; 79; 87; 88; 89; 97; 98; 99; 107; 117; 120; 340; 560; 3; 13; 14; 24; 34C; 34F; 34K; 34L; 34M; 34N; 33D; 33E; 33L; 33N; 32M; 42P; 43B; 43G; 43J; 43M; 43N; 54A; 54B; 54C; 54F; 54G; 54M; 55D; 55F; 55J; 55P
AreaAtlantic Ocean; Pacific Ocean; Arctic Ocean; Vancouver Island; Haida Gwaii; Pacific Coast; Atlantic Coast
Lat/Long WENS-144.0000 -122.0000 60.0000 48.0000
Lat/Long WENS -68.0000 -48.0000 52.0000 42.0000
Lat/Long WENS-141.0000 -56.0000 84.0000 51.0000
Subjectsenvironmental geology; marine geology; extraterrestrial geology; tsunami; health hazards; tidal wave; surface wave studies; coastal studies; coastal environment; shorelines; landslides; landslide deposits; slope failures; slope stability; geological hazards
Illustrationstables; location maps; plots; histograms
ProgramNational-Scale Geohazard Assessments, Public Safety Geoscience
AbstractWe present a preliminary probabilistic tsunami hazard assessment of Canadian coastlines from local and far-field, earthquake, and large submarine landslide sources. Analyses involve published historical, palaeotsunami and palaeoseismic data, modelling, and empirical relations between fault area, earthquake magnitude, and tsunami run-up. The cumulative estimated tsunami hazard for potentially damaging run-up (>1.5 m) of the outer Pacific coastline is ~40 - 80 % in 50 years, respectively one and two orders of magnitude greater than the outer Atlantic (~1 - 15 %) and the Arctic (<1 %). For larger run-up with significant damage potential (C3 m), Pacific hazard is ~10 - 30 % in 50 years, again much larger than both the Atlantic (~1 - 5 %) and Arctic (<1 %). For outer Pacific coastlines, the >1.5 m run-up hazard is dominated by far-field subduction zones, but the probability of run-up >3 m is highest for local megathrust sources, particularly the Cascadia subduction zone; thrust sources further north are also significant, as illustrated by the 2012 Haida Gwaii event. For Juan de Fuca and Georgia Straits, the Cascadia megathrust dominates the hazard at both levels. Tsunami hazard on the Atlantic coastline is dominated
by poorly constrained far-field subduction sources; a lesser hazard is posed by near-field continental slope failures similar to the 1929 Grand Banks event. Tsunami hazard on the Arctic coastline is poorly constrained, but is likely dominated by continental slope failures.
Summary(Plain Language Summary, not published)
This article presents the first national tsunami hazard assessment for Canada. It provides estimates of the hazard presented by tsunamis triggered by nearby and distant earthquakes and large submarine landslides. Tsunami hazard is greatest for the outer coast of British Columbia, where the most damaging tsunamis are expected from earthquakes on the Cascadia subduction zone. Tsunamis generated at other subduction zones, both nearby and distant, are also significant. Tsunami hazard is an order of magnitude less for the Atlantic coastline than the Pacific, and is dominated by poorly-understood distant subduction zones. A smaller hazard is presented by landslide tsunamis generated at the continental slope, similar to the 1929 Grand Banks event that caused 28 deaths in Newfoundland. Tsunami hazard is lowest for the Arctic coastline, but many areas here and on the Canadian coastline as a whole are susceptible to damaging waves triggered by local landslides.