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Oklahoma Earthquakes - Frequently Asked Questions

Report Feeling an Oklahoma Earthquake

Oklahoma Geological Survey Main Website

 

Preliminary Earthquake Report, November 5, 2011 (Updated)

 

Contacts: Austin Holland or Amie Gibson, Oklahoma Geological Survey, (Email Us)

On November 5, 2011 at 2:12 AM CDT (07:12:45.4 UTC) an magnitude 4.7 earthquake occurred in Lincoln County, Oklahoma.  This turned out to be a foreshock to a much larger earthquake.  The mainshock occurred at 10:53 PM CDT (11-6 03:53:10 UTC).  The main shock was followed by a magnitude 4.8 earthquake that occurred at 2011-11-07 8:46:57 PM CST.  The earthquakes occurred northwest of Prague and southeast of Sparks.  These earthquakes occurred very close to where a magnitude 4.3 earthquake occurred on February 27, 2010.  From the location of the earthquake and the focal mechanism it is most likely that this earthquake occurred on the Wilzetta fault also known as the Seminole uplift.  There have been over 200 aftershocks occurring in the area since the earthquakes began.  Most go unfelt, but felt earthquakes continue in the area.  We are currently working to locate the numerous aftershocks and we will continue to update information as we can.  For recent earthquakes visit our recent earthquakes page.

The OGS, University of Oklahoma School of Geology and Geopysics, Oklahoma State University, and the USGS have all been deploying temporary seismic stations within the area.  There have been more than 30 additional instruments deployed in the area.  This will allow researchers to learn as much as possible about the Wilzetta fault and its associated earthquake hazard.

Below are some images of earthquake locations and selected recordings.


 

USGS Event Page

Recordings from stations in Oklahoma.  Earthscope station V35A is the closest to this earthquake.
 
Snapshot of earthquake locations from the recent earthquakes page.  Black lines represent faults.  As you can see these earthquakes are clearly associated with a known fault.
 

 

 

The Oklahoma Geological Survey Observatory in rural Tulsa County, south of Leonard is a comprehensive
geophysical observatory which records, identifies, and locates  50 to 167 earthquakes in Oklahoma each year, and also records at least seven worldwide earthquakes per day.

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