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TitleA comparison of seismicity to the crustal deformation predicted by a glacial isostatic adjustment model in northern Canada and western Greenland
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AuthorJames, T S; Schamehorn, T D
SourceGeological Survey of Canada, Open File 8106, 2016, 24 pages, https://doi.org/10.4095/299098
Year2016
PublisherNatural Resources Canada
Documentopen file
Lang.English
Mediaon-line; digital
File formatreadme
File formatpdf; txt; rtf
ProvinceNunavut; Northern offshore region; Quebec; Newfoundland and Labrador; Ontario
NTS14; 15; 16; 24; 25; 26; 27; 28; 29; 34; 35; 36; 37; 38; 39; 44; 45; 46; 47; 48; 49; 54; 55; 56; 57; 58; 59; 64; 65; 66; 67; 68; 69; 120; 340; 560
AreaBaffin Island; Foxe Basin; Davis Strait; Hudson Bay; Canada; Greenland
Lat/Long WENS-100.0000 -40.0000 85.0000 55.0000
Subjectssurficial geology/geomorphology; geophysics; earthquake catalogues; earthquakes; seismicity; modelling; stress analyses; isostatic compensation; Bell Arch; Boothia Uplift
Illustrationslocation maps; plots; tables
ProgramWestern Canada Geohazards Project, Public Safety Geoscience
Released2016 11 08
AbstractThe horizontal crustal strain-rates induced by glacial isostatic adjustment (GIA) in northern Canada and western Greenland region are compared to the spatial pattern of seismicity to determine whether earthquakes occur where GIA-predicted crustal strain-rates are high. For the comparison, an updated seismicity catalogue was created from the 2010 version of the NRCan Seismic Hazard Earthquake Epicentre File (SHEEF2010) catalogue and the Greenland Ice Sheet Monitoring Network (GLISN) catalogue of the Geological Survey of Denmark and Greenland (GEUS). Crustal motion rates were computed using the Innu/Laur16 ice-sheet history and the VM5a viscosity profile. This GIA model optimizes the fit to relative sea-level and vertical crustal motion measurements around Hudson Bay and the Canadian Arctic Archipelago (CAA). A region in Baffin Bay where predicted GIA strain-rates are high also features historically high seismicity, including the 1933 M 7.4 and the 1934 and 1945 M 6.5 earthquakes. Elsewhere, agreement is not strong, with zones of seismicity occurring where predicted horizontal crustal strain-rates are small and large crustal strain-rates occurring where earthquake occurrence is muted. Further investigations could include calculation of crustal stress-rates so that failure criteria may be assessed for Baffin Bay events.
Summary(Plain Language Summary, not published)
The stretching and squeezing induced by glacial isostatic adjustment (GIA) in northern Canada and western Greenland is compared to the spatial pattern of earthquakes to determine whether earthquakes occur where GIA-predicted crustal strain-rates are high. For the comparison, an updated seismicity catalogue was created from two previously-existing catalogs. Crustal motion rates were computed for a recently published GIA model that simulates the Earth¿s response to the last Ice Age. This GIA model fits sea-level and vertical crustal motion observations better than previous models. A region in Baffin Bay where predicted GIA strain-rates are high also features historically high seismicity, including the 1933 M 7.4 and the 1934 and 1945 M 6.5 earthquakes. Elsewhere, agreement is not strong. Suggestions are made for further investigations.
GEOSCAN ID299098