HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by BENT, A. L. Articles by CASSIDY, J. F. Search for Related Content GeoRef GeoRef Citation

The January 1992 Franklin Lake, Northwest Territories, earthquake sequence

GEOPHYSICS DIVISION GEOLOGICAL SURVEY OF CANADA 1 OBSERVATORY CRESCENT, OTTAWA, ONTARIO, K1A 0Y3 Canada

Abstract

On 4 January 1992 an m_bLg 6.0 earthquake occurred in a relatively aseismic section of the Boothia-Ungava Seismic Zone near Franklin Lake in the eastern Northwest Territories and was the third large earthquake to have occurred in eastern Canada since 1988. We have determined the source properties of this earthquake by modeling both body and surface waves. The focal mechanism indicates a combination of thrust and strike-slip faulting on a northwest-striking plane, with the rupture initiating at a depth of 9 km. The P axis of this focal mechanism is consistent with those of nearby earthquakes and with the regional stress field, which is dominated by near-horizontal northeast compression. M_S and m_b are about one unit of magnitude less than m_bLg, which may be a result of directivity. There is some evidence based on a shift in corner frequency with azimuth that the fault ruptured to the southeast. Maximum likelihood estimates of the recurrence rates for the seismic zone suggest that, although the earthquake was unusually large for the immediate epicentral area, it was not anomalous with respect to the seismic zone as a whole. A comparative analysis of the mainshock and aftershocks indicates that the aftershocks tended to be shallower than the mainshock and probably had a larger component of dip-slip motion.

This article has been cited by other articles:

				A. L. Bent The 1989 (MS 6.3) Ungava, Quebec, earthquake: a complex intraplate event Bulletin of the Seismological Society of America, August 1, 1994; 84(4): 1075 - 1088. [Abstract] [PDF]