Strong aftershock M 6.3 struck Canada’s Haida Gwaii region – Aftershock list

strong-aftershock-m-6-3-struck-canadas-queen-sharlotte-islands-region-aftershock-list

Canada’s Haida Gwaii region struck strong aftershock at 18:54 UTC on October 28, 2012 according to USGS. This is still preliminary magnitude but the event was reviewed by seismologist. Epicenter was located 159 km (98 miles) SSW of Masset, Canada at coordinates 52.633°N, 132.701°W. Recorded depth was 8.2 km (5.1 miles).

EMSC reported this earthquake as magnitude 5.8 with depth of 5 km.

 

Magnitude 6.3
Date-Time
  • Sunday, October 28, 2012 at 18:54:21 UTC
  • Sunday, October 28, 2012 at 11:54:21 AM at epicenter
Location 52.633°N, 132.701°W
Depth 8.2 km (5.1 miles)
Region QUEEN CHARLOTTE ISLANDS REGION
Distances 159 km (98 miles) SSW of Masset, Canada
245 km (152 miles) SW of Prince Rupert, Canada
343 km (213 miles) SW of Terrace, Canada
595 km (369 miles) WNW of Campbell River, Canada
Location Uncertainty horizontal +/- 18.5 km (11.5 miles); depth +/- 6.5 km (4.0 miles)
Parameters NST=281, Nph=281, Dmin=317.3 km, Rmss=1.32 sec, Gp= 83°,
M-type=regional moment magnitude (Mw), Version=8
Source
  • Magnitude: USGS NEIC (WDCS-D)
    Location: USGS NEIC (WDCS-D)
Event ID usb000dg06

Mainshock details

Magnitude 7.7
Date-Time
  • Sunday, October 28, 2012 at 03:04:10 UTC
  • Saturday, October 27, 2012 at 08:04:10 PM at epicenter
Location 52.769°N, 131.927°W
Depth 17.5 km (10.9 miles)
Region QUEEN CHARLOTTE ISLANDS REGION
Distances 139 km (86 miles) S of Masset, Canada
202 km (125 miles) SSW of Prince Rupert, Canada
293 km (182 miles) SW of Terrace, Canada
556 km (345 miles) NW of Campbell River, Canada
Location Uncertainty horizontal +/- 14 km (8.7 miles); depth +/- 4 km (2.5 miles)
Parameters NST=716, Nph=716, Dmin=267.2 km, Rmss=0.95 sec, Gp= 58°,
M-type=regional moment magnitude (Mw), Version=A
Source
  • Magnitude: USGS NEIC (WDCS-D)
    Location: USGS NEIC (WDCS-D)
Event ID usb000df7n

 

Tectonic summary by USGS

The October 28th, 2012 (October 27 at the location of the epicenter) M 7.7 earthquake south of Masset, Canada, occurred as a result of oblique-thrust faulting near the plate boundary between the Pacific and North America plates. 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.This earthquake is likely associated with relative motion across the Queen Charlotte fault system offshore of British Columbia, Canada. Studies of tectonics in this region suggest plate motions are taken up by strike slip faulting parallel to the plate boundary, accompanied by lesser amounts of thrust motion to accommodate the oblique nature of the plate motion vector between the two plates with respect to the orientation of the main plate boundary fault structure. This oblique component of plate motion may involve either underthrusting of the western edge of the Pacific Plate beneath North America, or be taken up on crustal faults within the North America plate. The October 28th earthquake is consistent with either scenario. Its rupture extended approximately 100-150 km along strike, along the shallow extent of the source fault. Slip amounts reached approximately 5m, in a patch to the south of the epicenter. Aftershocks delineate the rupture well, as shown here.

This region of the Pacific:North America plate boundary has hosted 7 earthquakes of magnitude 6 or greater over the past 40 years – the largest of which was a M 6.6 earthquake in 2009, 80 km to the south east of the 2012 earthquake. In 1949, a M 8.1 earthquake occurred closer to the Pacific:North America plate boundary, likely as a result of strike-slip faulting, approximately 100 km northwest of the October 28th earthquake, near the northern extent of Haida Gwaii region (formerly Queen Charlotte Islands). Summary report.

Aftershock list

 

Update time = Sunday, October 28, 2012 – 19:48:04 UTC, Source: USGS

MAG UTC DATE-TIME
y/m/d h:m:s
LAT
deg
LON
deg
DEPTH
km
 Region
 5.1   2012/10/28 19:16:56   52.555  -132.496 47.6  QUEEN CHARLOTTE ISLANDS REGION
 5.5   2012/10/28 19:09:56   52.315  -131.860 14.8  QUEEN CHARLOTTE ISLANDS REGION
 5.4   2012/10/28 19:03:25   52.742  -132.901 32.8  QUEEN CHARLOTTE ISLANDS REGION
 6.3   2012/10/28 18:54:22   52.633  -132.701 8.2  QUEEN CHARLOTTE ISLANDS REGION
 5.1   2012/10/28 16:17:04   52.380  -131.664 15.0  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 15:24:22   52.803  -132.113 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.0 2012/10/28 15:10:34   52.516  -132.066 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.4 2012/10/28 15:06:55   52.417  -132.169 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.0 2012/10/28 14:14:29   52.588  -131.440 7.7  QUEEN CHARLOTTE ISLANDS REGION
 4.2 2012/10/28 14:04:28   52.635  -132.403 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.1 2012/10/28 13:45:49   51.127  -130.305 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.8   2012/10/28 13:09:14   52.432  -131.882 10.2  QUEEN CHARLOTTE ISLANDS REGION
 4.1 2012/10/28 12:38:46   52.870  -132.204 10.1  QUEEN CHARLOTTE ISLANDS REGION
 4.0 2012/10/28 12:18:00   52.689  -131.870 9.8  QUEEN CHARLOTTE ISLANDS REGION
 4.1 2012/10/28 12:09:43   52.568  -132.065 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.7   2012/10/28 11:53:21   52.438  -132.201 10.5  QUEEN CHARLOTTE ISLANDS REGION
 4.8   2012/10/28 11:27:46   52.395  -132.161 11.1  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 11:17:23   52.400  -131.565 10.6  QUEEN CHARLOTTE ISLANDS REGION
 4.0 2012/10/28 10:59:15   52.477  -131.769 9.7  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 10:50:33   52.484  -131.945 10.3  QUEEN CHARLOTTE ISLANDS REGION
 4.7   2012/10/28 10:45:50   52.621  -132.500 10.2  QUEEN CHARLOTTE ISLANDS REGION
 4.5   2012/10/28 10:23:09   52.753  -132.678 10.2  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 10:10:28   52.482  -132.248 10.3  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 10:04:38   52.924  -132.395 10.3  QUEEN CHARLOTTE ISLANDS REGION
 4.1 2012/10/28 09:52:59   52.892  -131.733 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.4 2012/10/28 09:45:39   52.886  -132.392 10.2  QUEEN CHARLOTTE ISLANDS REGION
 4.4 2012/10/28 09:41:17   52.029  -132.187 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.6   2012/10/28 09:36:37   52.258  -132.343 10.3  QUEEN CHARLOTTE ISLANDS REGION
 4.4 2012/10/28 09:22:50   52.467  -131.439 10.7  QUEEN CHARLOTTE ISLANDS REGION
 5.1   2012/10/28 09:17:28   52.216  -132.006 10.5  QUEEN CHARLOTTE ISLANDS REGION
 4.2 2012/10/28 09:15:49   52.102  -131.653 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 08:22:04   52.066  -132.073 10.0  QUEEN CHARLOTTE ISLANDS REGION
 5.0   2012/10/28 07:25:22   52.270  -131.493 10.6  QUEEN CHARLOTTE ISLANDS REGION
 4.9   2012/10/28 07:16:38   52.775  -132.456 11.4  QUEEN CHARLOTTE ISLANDS REGION
 4.6   2012/10/28 07:12:14   52.109  -132.221 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.4 2012/10/28 07:02:19   51.941  -131.836 10.8  QUEEN CHARLOTTE ISLANDS REGION
 5.0   2012/10/28 06:16:53   52.268  -131.212 11.5  QUEEN CHARLOTTE ISLANDS REGION
 4.5   2012/10/28 05:51:17   52.815  -132.714 10.3  QUEEN CHARLOTTE ISLANDS REGION
 4.2 2012/10/28 05:47:09   52.429  -131.451 10.1  QUEEN CHARLOTTE ISLANDS REGION
 4.1 2012/10/28 05:38:38   51.786  -132.312 10.1  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 05:21:37   52.139  -131.571 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 05:15:13   52.499  -132.222 10.1  QUEEN CHARLOTTE ISLANDS REGION
 4.5   2012/10/28 05:02:50   52.409  -132.165 10.3  QUEEN CHARLOTTE ISLANDS REGION
 4.3 2012/10/28 04:54:46   52.403  -132.439 10.1  QUEEN CHARLOTTE ISLANDS REGION
 4.7   2012/10/28 04:41:05   52.592  -132.670 10.0  QUEEN CHARLOTTE ISLANDS REGION
 4.6   2012/10/28 04:33:51   52.906  -133.120 10.0  QUEEN CHARLOTTE ISLANDS REGION
 5.1   2012/10/28 04:25:17   52.019  -133.370 10.1  QUEEN CHARLOTTE ISLANDS REGION
 4.8   2012/10/28 03:52:25   52.199  -131.986 10.9  QUEEN CHARLOTTE ISLANDS REGION
 7.7   2012/10/28 03:04:11   52.769  -131.927 17.5  QUEEN CHARLOTTE ISLANDS REGION
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One Comment

  1. I have a contingency plan and my bug-out-bag is gtg in the event EQs unzip land mass and displace salt water along the Pacific coast. I am 50 yards away from the Pacific ocean shoreline and I am concerned about the rumbles me and others have experienced in the past few weeks.

    Many of us have plans to move far away from the ocean as possible including a move to another state. As scenic as it is to live here it is becoming a hazard as tsunami warnings were blasted over the beach speaker system last night and again today. I have noticed in the past few weeks the beach tsunami warning system has been tested and on alert as EQs and tremors become more frequent.

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