Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Geophysics

Supervisor

Dr. Gail Atkinson

Abstract

The Charlevoix Seismic Zone (CSZ) is the most seismically active region in eastern Canada, based on the historical and current rate of activity. Several papers contend that the current seismicity in the CSZ represents long-lived aftershock sequences of the 1663 M~7 earthquake, in which the aftershock activity has persisted for hundreds of years. The aim of this thesis is to explore the influence of the 1663 earthquake on the current seismicity in the CSZ. The first part of the thesis has focused on developing a comprehensive earthquake database required for analysis of seismicity. The second part of the thesis has been devoted to characterization of seismicity in the CSZ in both time and space, with the goal of developing greater insight into the nature of intraplate seismicity in this region. The evidence from statistical analysis suggests that the current seismicity in the CSZ is not predominantly composed of the aftershock activity of past large earthquakes; the ongoing seismicity is therefore expected to continue in the region, and the zone should be considered an ongoing source of seismic hazard. However, we emphasize that this does not eliminate the possibility that earthquake activity in Charlevoix is still influenced by the stress changes imparted by the 1663 earthquake in the surrounding crust. The Coulomb stress analysis used in the present thesis shows that the stress triggers and shadow cast by the 1663 earthquake still exert influence on earthquake occurrence in Charlevoix after centuries.


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