Saturday, October 27, 2012

Very Large 7.7 Mag Quake Reported Off Of Canada

A magnitude 7.7 Earthquake has struck off of Canada's West Coast near Graham Island Queen Charlotte Island. The depth was a shallow 9km deep, along the Pacific subduction zone. It is unclear if there was any damage or if a tsunami has been generated. The quake occurred at 8PM which is only a few minutes after I am writing this. Below is a screenshot of the epicenter location.



Google Earth/USGS snapshot of location of 7.7 mag quake.

Aside from the linked article above, this quake is so fresh that nobody yet knows the implications. I will update this article as more info becomes available.
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Image from USGS.gov detailing the shake strength of the quake.

UPDATE: According to WFAA a tsunami alert was issued from Vancouver Island, British Columbia to Cape Decision, Alaska. Residents are urged to move to higher ground. This is likely a precaution but if you are in the area please do not hesitate to seek higher ground.

A mag 5.8 afterschock occurred a few miles SW of the epicenter.

The island is lightly populated by what appear to be logging towns. Looking at Google Earth reveals several towns in the area nearest the epicenter. Those towns are:

Sewell Inlet
Skedans Village
New Clew
Sandspit
Skidegate
Queen Charlotte
Tlell
Port Clements

It is likely that these towns sustained some damage, but reports will likely be slow to come from the region.

Here is an update from the Tsunami Center:

From: tsunami-information-ioc@lists.unesco.org
Date: October 27, 2012, 11:14:14 PM EDT
To: IOC_Public_Lists@ptwc.noaa.gov
Subject: [Tsunami Message - IOC] Tsunami Information Bulletin
Reply-To: tsunami-information-ioc@lists.unesco.org

TSUNAMI BULLETIN NUMBER 001

PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS ISSUED AT 0313Z 28 OCT 2012 THIS BULLETIN APPLIES TO AREAS WITHIN AND BORDERING THE PACIFIC OCEAN AND ADJACENT SEAS...EXCEPT ALASKA...BRITISH COLUMBIA... WASHINGTON...OREGON AND CALIFORNIA. ... TSUNAMI INFORMATION BULLETIN ... THIS BULLETIN IS FOR INFORMATION ONLY. THIS BULLETIN IS ISSUED AS ADVICE TO GOVERNMENT AGENCIES. ONLY NATIONAL AND LOCAL GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKE DECISIONS REGARDING THE OFFICIAL STATE OF ALERT IN THEIR AREA AND ANY ACTIONS TO BE TAKEN IN RESPONSE.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS ORIGIN TIME - 0304Z 28 OCT 2012 COORDINATES - 52.9 NORTH 131.9 WEST DEPTH - 10 KM LOCATION - QUEEN CHARLOTTE ISLANDS REGION MAGNITUDE - 7.1 EVALUATION A WIDESPREAD DESTRUCTIVE TSUNAMI THREAT DOES NOT EXIST BASED ON HISTORICAL EARTHQUAKE AND TSUNAMI DATA. THE WEST COAST AND ALASKA TSUNAMI WARNING CENTER WILL ISSUE INFORMATION REGARDING ANY LOCAL TSUNAMI THREAT TO COASTS NEAR THE EARTHQUAKE EPICENTER.

THIS WILL BE THE ONLY BULLETIN ISSUED FOR THIS EVENT UNLESS ADDITIONAL INFORMATION BECOMES AVAILABLE. THE WEST COAST/ALASKA TSUNAMI WARNING CENTER WILL ISSUE PRODUCTS FOR ALASKA...BRITISH COLUMBIA...WASHINGTON...OREGON...CALIFORNIA.

The information provided on this email service does not originate with UNESCO. UNESCO is transmitting this information on an unofficial basis. The official warning messages are sent by governmental authorities through the Tsunami Warning Focal Points (TWFP) and the designated national authorities. UNESCO does not warrant, guarantee, or make any representations regarding the timeliness, currency, correctness, accuracy, reliability, or other aspect of the characteristics or use of the information available through this email service.


UPDATE:

CNN is now covering the story and has a live blog of all developments at http://news.blogs.cnn.com/2012/10/27/quake-with-a-magnitude-of-7-7-strikes-off-canada-coast/?hpt=hp_t1

UPDATE

so far 13 aftershocks ranging from 4.0-58 have occurred. Likely aftershocks will continue for up to a week or longer, with diminishing magnitudes.

3 comments:

  1. Do we know if this is connected with Cascadia subduction zone?

    J.bradbury at preparepdx.com

    ReplyDelete
  2. This is associated with the same b=plate boundary, however the Cascadia subduction zone is further South off the coasts of Washington, Oregon, and Northern California.

    ReplyDelete

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