ABSTRACT
Eastern Canada, especially the southern portion of Quebec province, is a stable continental region prone to earthquakes. An historical earthquakes of up to a magnitude of approximately 7.9 occurred in 1663, and the exact location of the epicenter is still being debated. However, multiple landslides were triggered by this earthquake. These landslides, subaqueous and subaerial, in rock or in soil, are spread over an area of about 85 000 km2.
Here, we use the SPECFEM3D Cartesian software which uses the continuous Galerkin spectral-element method to simulate elastic wave propagation caused by earthquakes to look at the effect of source location and topography of the region, in association with the location of various landslides that were known to be caused by the 1663 earthquake, in order to analyze the possible location of the 1663 earthquake epicenter. As possible source location, we used the different 1663 epicenter position published in the literature, as well as the position of a more recent earthquake in the region, which had a lower magnitude. Using the PGA as a proxy to compare the different earthquake locations or mechanism, we were not able to found one proposed epicenter location that would provide enough high PGA to trigger all the landslides. However, it is possible to conclude that, the earthquake location is likely to have been located north of the Charlevoix seismic zone, but South to the Baie des Ha!Ha!, in the Saguenay region.
