Magnitude 2.6 Microearthquake in Portland

November 6, 2006 at 05:34:35 UTC

(Sunday, November 5, 09:34:35 Local Time)
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Robert Butler & John Lahr

Epicenter: Latitude 45.516°N, 122.648°W (indicated by star on map; and red square on aerial photo).  Depth: approximately 15.7 kilometers but not very precise.  Map on bottom right shows intensity based on Internet reports from residents.

 

                                                                         

 

  
Google Earth view of the M 2.6 earthquake of November 6, 2006.  Faults: Orange -- East Bank fault;
 Purple -- Portland Hills Fault.

 

 

 

 

Initially thought was that the earthquake occurred on the Portland Hills Fault but the revised location is more consistent with motion on the East Bank Fault. It is also possible that the earthquake took place on an unmapped fault.

 

Short-period record from Corvallis, Oregon, station (COR).

 

 

References and further reading

 

Richard L. Hill, The Oregonian article, November 07, 2006:  Third S.E. Portland quake poses puzzle for experts. http://www.oregonlive.com/news/oregonian/index.ssf?/base/news/1162869917236570.xml&coll=7

 

USGS Did You Feel It? web site:  http://pasadena.wr.usgs.gov/shake/STORE/X11060534/ciim_form.html

 

Airborne Hunt for Earthquake Hazards in the Portland-Vancouver Area http://geophysics.wr.usgs.gov/gump/portland/portland.html

 

U.S. Geological Survey, 2006, Quaternary fault and fold database for the United States, accessed November 6, 2006, from USGS web site: http://earthquakes.usgs.gov/regional/qfaults/ .

 

East Bank Fault:

http://gldims.cr.usgs.gov/webapps/cfusion/Sites/qfault/qf_web_disp.cfm?qfault_or=1734&qfault_id=876

 

Portland Hills Fault:

http://gldims.cr.usgs.gov/webapps/cfusion/Sites/qfault/qf_web_disp.cfm?qfault_or=1735&qfault_id=877

 

Oatfield Fault:

http://gldims.cr.usgs.gov/webapps/cfusion/Sites/qfault/qf_web_disp.cfm?qfault_or=1733&qfault_id=875

 

 

Last updated 11/23/2006