Earth Watch Report - Earthquakes
|Location Uncertainty||Horizontal: 14.2 km; Vertical 5.3 km|
|Parameters||Nph = 205; Dmin = 193.8 km; Rmss = 1.48 seconds; Gp = 68°
Version = 8
|Event ID||us b000jg6b|
For updates, maps, and technical information, see: Event Page or USGS Earthquake Hazards Program
National Earthquake Information Center
U.S. Geological Survey
The September 3, 2013 earthquake occurred as the result of strike-slip faulting in the boundary region between the Pacific plate, the North American plate, and the Juan de Fuca plate (or the Explorer subplate of the Juan de Fuca plate). The epicenter is situated south of Haida Gwaii, also known as the Queen Charlotte Islands, off the west coast of British Columbia. At the location of this event, the Pacific plate moves approximately north-northwest with respect to the North America plate at a rate of approximately 50 mm/yr. The focal-mechanism of the shock is consistent with right-lateral slip on a fault approximately parallel to the direction of relative motion between the Pacific and North American plates. The region of the earthquake has complex geologic structure, however, and strike-slip motion on an east-northeast left-lateral fault that is perpendicular to the trend of the broad-scale plate boundary is also compatible with the focal mechanism and cannot be ruled out.
The region of the September 3, 2013, earthquake has a history of frequent moderate and large earthquakes. Since 1973, three other earthquakes of magnitude 6 or greater have occurred within 50 km of the epicenter of the September 3, 2013 shock, the largest of which had magnitude 6.6. The epicenter of the magnitude 7.8 Haida Gwaii earthquake of October 28, 2012, was situated on the Pacific/North American plate boundary approximately 225 km to the north-northwest.
5.9 163km SW of Bella Bella, Canada 2013-09-03 19:23:12 UTC-05:00 9.9 km
4.2 179km WSW of Bella Bella, Canada 2013-09-03 18:07:08 UTC-05:00 10.0 km
5.0 188km SW of Bella Bella, Canada 2013-09-03 17:29:32 UTC-05:00 9.8 km
4.8 183km SW of Bella Bella, Canada 2013-09-03 16:25:18 UTC-05:00 10.2 km
4.6 181km SW of Bella Bella, Canada 2013-09-03 16:05:58 UTC-05:00 10.5 km