GEOSCAN, résultats de la recherche


TitreEarthquakes in southwestern British Columbia
AuteurBird, A L
SourceBase Operations March 31, 2008 p. 2
Séries alt.Secteur des sciences de la Terre, Contribution externe 20070610
ÉditeurNewsletter of Canadian Forces Base at Esquimalt
Documentpublication en série
SNRC92; 102I; 102P
Lat/Long OENS-130.0000 -120.0000 52.0000 48.0000
Sujetssecousses séismiques; études séismiques; risque de tremblement de terre; catalogues des tremblements de terre; magnitudes des séismes; foyers des séismes; sismographes; réseau sismique; séismologie; dangers pour la santé; secousses séismiques; dégât causés par les tremblements de terre; magnitudes des séismes; risque de tremblement de terre; études séismiques; séismologie; Zone de subduction de Cascadia ; Plaque de Juan de Fuca; Réseau national sismologique canadien; géophysique; tectonique; géophysique; géologie éducative
Illustrationslocation maps; photographs; block diagrams
ProgrammeService d'information sur les dangers naturels au Canada
Résumé(disponible en anglais seulement)
The west coast of British Columbia accommodates all three major types of plate boundary. Most dramatically, the 1000km-long Cascadia Subduction Zone, approximately 150 km west of Vancouver Island, is where the oceanic Juan de Fuca Plate subducts beneath the North American Plate. This is the most seismically hazardous area in the country, including a history of megathrust earthquakes, plus more frequent strong earthquakes within the two plates. The pressure from this locked plate interface causes the 30km-thick North American Plate to bend, inducing earthquakes as large as 7.5; the highest source of hazard in the region is based on such earthquakes, particularly those occuring close to population centres. Large earthquakes (magnitude ~7) can also occur within the Juan de Fuca Plate as it bends during its subduction beneath North America.

Due to the active tectonics and resulting, daily earthquakes of British Columbia, earthquake seismologists and emergency managers rely on cohesive communication to respond effectively and efficiently. Several earthquakes are felt by BC citizens every year; Natural Resources Canada works together with emergency programmes to provide emergency services, the press and public with timely, accurate information. By responding to these earthquakes together, protocols are honed and liaisons are developed, putting the agencies in good stead for the larger, damaging earthquakes which threaten this region.