Unlike plate margins where the seismic activity is directly correlated with plate interactions, eastern Canada earthquakes lie in the "stable" interior of the North American Plate. The driving mechanisms of intra-plate earthquakes are more difficult to determine. In addition, the hazard posed by potentially devastating earthquakes for this region is not well constrained due to limitations of the probabilistic seismic hazard estimation method (e.g., the inexact nature of extrapolating the rate of occurrence of frequent small events to the occurrence of infrequent larger events, relatively short instrumental and historical records, and limited palaeoseismic evidence for past large events) (Henton et al. 2006).
Henton, J. A., Raymer, M. R., Ferland, R., Dragert, H., Mazzotti, S., and Forbes, D. L. (2006). Crustal motion and deformation monitoring of the Canadian landmass. Geomatica, 60(2), 173-191.