A closer look at the September 16, 1732, Montreal earthquake

Abstract

The September 16, 1732, earthquake ranks among the three largest events in the western Quebec zone of earthquake occurrence and thus plays a controlling role in seismic hazard studies of the region. Its epicentral intensity has been estimated differently by various authors of earthquake catalogues, mostly because limited information was available. Recently, additional evidence was uncovered and evaluated. It suggests that an epicentral intensity VIII (modified Mercalli) is adequately representative of the damage observed in Montreal and agrees well with the other distant felt reports. On that basis, the intensity IX (MM) found in some catalogues should be revised; on the other hand, the Montreal location appears to be the most acceptable. It is proposed that the event be also characterized in terms of an estimated magnitude range, i.e., 5.6–6.0 [Formula: see text].