Deborah (16 June 2005)
"7.2M Tectonic Summary - USGS"


 
Tectonic Summary

Magnitude 7.2 OFF COAST OF NORTHERN CALIFORNIA 
Wednesday, June 15, 2005 at 02:50:54 UTC

Preliminary Earthquake Report
U.S. Geological Survey, National Earthquake Information Center
World Data Center for Seismology, Denver
This earthquake occurred in a deformed section of the southernmost Juan de Fuca plate that is commonly called the Gorda plate. The epicenter lies to the west of the Cascadia Subduction Zone. Light shaking from this earthquake was widely felt along the northern California - southern Oregon coastline.

Preliminary analysis of the quake indicates that it resulted from slip on a NE striking, left-lateral, strike-slip fault; this type of mechanism has been documented for other earthquakes having locations in the interior of the Gorda plate. This earthquake did not produce a tsunami. Earthquakes with strike-slip mechanisms are less likely to produce tsunamis because they cause relatively little vertical ground displacement.

Earthquakes are common in the Gorda plate, which is subjected to north-south compression due to the north-west moving Pacific Plate that collides with the southern boundary of the Gorda Plate along the east-west Mendocino Fracture Zone. This quake occurred approximately 67 miles west of the epicenter of the November 8, 1980 7.2M earthquake. There have been 3 other quakes of magnitude M>6 that have occurred with 50 miles radius of the epicenter of this quake (August 16, 17 1991 and July 24 1996).


Date:June 15, 2005 at 17:43:11
From:amg
Subject:7.2 Tectonic Summary>USGS
URL:http://neic.usgs.gov/neis/bulletin/neic_ziae_ts.html
 

There is a history for these kinds of earthquakes in the Gorda Plate area. The link gives some good details and a brief history of the area. I would put the foreshock probability for something larger in this area fairly low.

amg 

  Based upon the above history, this area has a history of one time main shocks in the 7M category.  So, they don't think there will be any further activity in THIS particular area.  This lucky stiffs have had their "BIG ONE"......and it was a sleeper!  No damage reports and no injuries.  The rest of us, won't get off so easy.......but maybe we will.....we'll see ALL depends upon exactly WHERE they hit.  Pray that they hit in remote areas!

 
 
 
 
 
 

Maranatha!
Deborah
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