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TitreRecurrence rates and b values for global in-slab earthquakes
TéléchargerTéléchargements
AuteurBent, A L; Greene, H
SourceCommission géologique du Canada, Dossier public 7001, 2012, 60 pages, https://doi.org/10.4095/289862
Année2012
ÉditeurRessources naturelles Canada
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/289862
Mediaen ligne; numérique
Formatspdf
ProvinceColombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon; Nunavut
SNRC1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Lat/Long OENS-180.0000 180.0000 90.0000 -90.0000
Sujetssecousses séismiques; études séismiques; mécanismes de tremblement de terre; interpretations sismiques; zones sismiques; sismicité; zones de subduction; subduction; Zone de subduction de Cascadia ; géophysique; tectonique
Illustrationstables; location maps; graphs; plots
Consultation
Endroit
 
Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre)
 
ProgrammeService d'information sur les dangers naturels au Canada, Service d'information sur les dangers naturels au Canada
Diffusé2012 02 06
Résumé(disponible en anglais seulement)
The b value, a measure of the relative number of large and small earthquakes, for the Cascadia subduction zone off the coast of southern British Columbia is low (0.44-0.74) when compared to other seismic zones in Canada and to global averages (0.65-1.1.0). The hazard for this region is dominated by in-slab earthquakes, or those that occur within the subducting slab rather than at the slab interface. It has not been known whether the low b value is a characteristic of in-slab earthquakes or whether Cascadia is truly anomalous. This study evaluates in-slab earthquakes worldwide and finds that on average the b values are comparable to those for other types of earthquakes and suggests that Cascadia is unusual. These results are based on earthquakes of magnitude 5.5 or greater obtained from a global database, which has sufficient information to separate in-slab events from slab interface and shallow crustal earthquakes in the same subduction zone. Regional databases would be useful for extending the magnitude range studied but generally do not have the resolution required to reliably separate the events. We compare the b values and magnitude 7 recurrence intervals to physical properties of the subduction zones, such as age, dip angle and rate of subduction and find no obvious correlations.
GEOSCAN ID289862