7:40 a.m. Shaw Group Analysis of Seismic Activity

Following recent reports of seismic activity on the western side of the Napoleonville Salt Dome, the Office of Conservation asked Dr. Gary Hecox with Shaw Environmental and Infrastructure to evaluate the readings from the USGS monitoring equipment.

Below is Dr. Hecox’s analysis:

On Tuesday October 23, 2012 at 9:06 PM a short duration, pronounced seismic event was recorded at the site.  The Center for  Earthquake Research and Information (CERI) was able to determine that this event occurred at a depth of approximately 500 meters (1,600 feet).  Shaw has reviewed the data from the cavern pressure monitoring system and sinkhole bubble activity.  The seismic event did not have any discernible effect on cavern pressure or sinkhole bubble activity.  No new bubble sites have been observed since this event occurred and activity at existing bubble sites has not visibly changed.