This update is the 19th article in this Opednews series about the Bayou Corne sinkhole.
BACKGROUND: In Spring of 2012, Louisiana's Corne and Grand Bayou residents noticed strange bubbling in the bayou for many weeks, and they reported smelling burnt diesel fuel and sulfur. Suddenly a sinkhole estimated to be the size of two or three football fields appeared on Aug. 3, swallowing scores of 100-foot tall cypress trees. The sinkhole resulted from the failure of Texas Brine Company's abandoned underground brine cavern. The Department of Natural Resources issued a Declaration of Emergency on Aug. 6, and 150 families were evacuated.
For maps, diagrams and additional information, please see the 18 previous installments in this series, listed at the end of this article.
A year after the largest sinkhole ever documented appeared, the cavity is almost 30 times larger, and containment does not appear to be any closer.
Liberty Island, at approximately 14 acres in size, could fit into the sinkhole twice!
According to the Assumption Parish Police Jury's Press Release on the day the sinkhole was discovered, Aug., 3, 2012, it was originally about 200' x 200', just under a square acre (which is 208.7' x 208.7').
However cave-ins have continued, enlarging it to its current monumental size.
Photos below are offered for comparison, showing how the size the of the sinkhole expanded between August 2012 and August 2013. (Although camera angles are slightly different, the sizes and positions of the two white cylindrical storage containers in the background of each photo can be used as an aid for comparison.)
On Wed. Aug 21, at 3:25 pm Central time, the Assumption Parish Police Jury noted, "There has been another burp that occurred and is continuing on the sinkhole. All operations have been pulled from inside of the sinkhole until activity calms down. The monitoring/alert status has been heightened to Code 3."
Sinkhole "burps" have heralded cave-ins in the past. And at about 7:15 that evening, a dramatic cave-in was captured on video, with huge trees disappearing quickly into the depths of the sinkhole. Watch carefully for the beginning of visible tree movement at 0:18. More than a dozen huge trees disappear under the water in about 20 seconds, and the video continues, showing the water movements in the aftermath of the descent.
The Assumption Parish Police Jury has noted in previous communications that Code 3 "restricts all work inside the containment berm, indicates seismic activity has elevated to a point similar to what has been seen in past monitoring prior to a sloughing on the shore or movement beneath sinkhole (More than 50 MEQs or VLPs in 24 hours)"
MEQs are sharp seismic signals associated with rock movement, called mini-earthquakes. Longer signals associated with gas or liquid movement are called Very Long Periods (VLPs.)