A Quantitative Analysis of Deglaciation as a Possible Earthquake Mechanism in Canada.
Bent, Allison L.
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With the exception of earthquakes occurring along the Pacific coast, earthquakes in Canada cannot be explained by plate tectonic theory. Deglaciation has been proposed as a possible cause of non-tectonic Canadian earthquakes. The main objective of this study was to determine, through the use of computer models, whether earthquakes in Canada are caused by post-glacial uplift. The observed seismic moment densities in all parts of Canada were determined from the magnitudes of about 10000 earthquakes occurring over a 400 year time interval. The theoretical seismic moment densities were calculated from the strain rates associated with the retreat of the Laurentide ice sheet. The model used to approximate the removal of the ice sheet was based on the work of Peltier and Andrews (1976). Contour maps of both the theoretical and observed seismic moment densities were made in order to compare the magnitude and distribution of actual and predicted seismicity. Although the distribution patterns differ somewhat, in all areas the predicted seismicity due to deglaciation is sufficient to account for the observed seismicity. Kwywords: Pages: 54 Supervisor: James Hall