Preliminary Results From the November 25, 1988 Saguenay (QUEBEC) Earthquake

• DOI: 10.1785/gssrl.60.3.89
• Publication Date: 2019-07-25T20:54:43Z
• Authors: Robert G. North; Robert J. Wetmiller; John Adams; Frank M. Anglin; Henry S. Hasegawa; Maurice Lamontagne; Reynald Du Berger; Leonardo Seeber; John Armbruster
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Abstract The November 25, 1988 Saguenay, Québec earthquake (mb 5.9) was preceded by a foreshock 62 hours earlier 4.4) and followed over 50 aftershocks, of which only two have been larger than magnitude 3. unusually large 29 km depth the main shock is well determined using field network deployed after foreshock. Nearly all aftershock activity shallower shock, suggesting that rupture propagated upwards. event produced unexpectedly amounts high frequency energy, as evidenced value mbLg (6.5) accelerations observed at distances ranging from 40 to 800 km. Focal mechanisms for foreshock, largest indicate thrust faulting. felt area exceeds 3.5 million km2 closely approaches 1925 Charlevoix earthquake. location Saguenay in region with little historic seismicity, its depth, high-frequency generation, pose several problems existing models seismic zoning hazard assessment Eastern North America.