The sinkhole in Assumption Parish, Louisiana has opened up quite a bit more and the drilling has discovered the bottom of the cavern too soon.
Early morning 20 September, about twenty-five feet of embankment fell into the sinkhole from the east side, taking several trees with it.
On 22 September, the drill entered the cavern. No gas was detected at that time, but a few hours later, natural gas began flowing from the cavern. Testing on the cavern and on samples from the cavern began the next day.
Texas Brine Company sent out a press release on 24 September 2012 stating that the drill had hit the cavern floor at about 4000 feet, which was 1300 feet sooner than expected. A “dense material” covered the floor of the cavern and was retrieved for analysis. They also stated that the cavern had collapsed due to seismic activity in the area.
Parish officials and the USGS dispute that assessment, saying that it’s much more likely that the regional seismic activity was caused by the cavern collapsing.
After the Texas Brine Company issued the press release, the Office of Conservation demanded the studies and date the company used to show seismic activity as the cause of the cavern collapse. They also required that Texas Brine report immediately to them all findings, including well logs, activity logs, test results, and changes to the cavern status.
Sometime in the late hours of 25 Sep or the early hours of 26 Sep, more of the sinkhole fell in, this time from the southeast side. A thirty foot by fifty foot section fell in, taking trees and part of the road that was built for cleanup activities.
Tests are still being performed on the samples brought up from the cavern and the sonar and well logs are being analyzed. Results will be published as soon as the reviews are complete.
The latest flyover video is below. This one is from 27 Sep 2012. You can see where the road fell in a bit. A rig site flyover is below that, also taken on 27 Sep 2012.