GEOSCAN Search Results: Fastlink

GEOSCAN Menu


TitleRecurrence rates and b values for global in-slab earthquakes
DownloadDownloads
AuthorBent, A L; Greene, H
SourceGeological Survey of Canada, Open File 7001, 2012, 60 pages, https://doi.org/10.4095/289862
Year2012
PublisherNatural Resources Canada
Documentopen file
Lang.English
Mediaon-line; digital
File formatpdf
ProvinceBritish Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS1; 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
Areaworld
Lat/Long WENS-180.0000 180.0000 90.0000 -90.0000
Subjectsgeophysics; tectonics; earthquakes; earthquake studies; earthquake mechanisms; seismic interpretations; seismic zones; seismicity; subduction zones; subduction; Cascadia Subduction Zone
Illustrationstables; location maps; graphs; plots
Viewing
Location
 
Natural Resources Canada Library - Ottawa (Earth Sciences)
 
ProgramCanadian Hazard Information Service, Canadian Hazard Information Service
Released2012 02 06
AbstractThe 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