9:40 a.m. Slough In Area

Below is a link to a map of the sinkhole area. The traced red line overlaying the photo depicts the area and size of the slough in that was reported to us on yesterday afternoon.

For future reference It has also been linked to the Police Jury website at:


5:45 p.m. Slough In Reported

It has been reported that a large slough in just occurred at the sinkhole site. The size is estimated to be a 20′ by 80′ section located on the east side of the sinkhole. No additional details are available at this time.

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.

10:45 p.m. Seismic Activity Reported

It has been reported to us that there was a sharp tremor recorded by USGS monitors at approximately  9:06 last night. The tremor was large enough that the body wave phases could easily be identified. The preliminary location was just SE of Oxy #3 cavern at a depth of 500m.  There is no additional information specific to this seismic activity at this time.

8:00 a.m. Meeting Presentation

We’ve received many requests for the slides that The Shaw Group presented at the briefing this past Tuesday night. Please know that we have requested this information and will post it to the blog and website as soon as we receive it.