Louisiana 25-acre sinkhole brings mini-earthquakes, explosion fears

An editor's note follows this story. 

Scientists are now saying they will need to monitor for decades an enormous -- and growing -- Louisiana sinkhole that has forced hundreds to evacuate and has been registering increased seismic activity, including mini-earthquakes.

What is known as the Bayou Corne sinkhole in southern Louisiana is now reportedly 25 or so acres in size and 200 feet deep, having opened in August 2012 when the wall of a subterranean salt mine collapsed and the ground above it was seemingly swallowed by the earth. It has since filled with water.

"While it was a manmade action that started this, it’s geology and natural forces that are making everything happen," Patrick Courreges, a policy analyst for the Louisiana Dept. of Natural Resources, told TheVerge.com. "And geology happens slow."

When it occurred, Assumption Parish reportedly ordered the 300-or-so nearby residents to evacuate their homes. Hundreds have done so, although more than a few have remained behind, regardless of the danger.

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According to TheVerge.com, recent studies show a good deal more methane gas than the initial estimate of 45 million cubic feet have leaked into a nearby aquifer and, “the fear is that the highly combustible gas will collect in a crevice or enclosed space and then ignite.”

Texas Brine Co., the salt mine's former operator, told FoxNews.com that figure was a high estimate from October -- and said fears of an explosion are unjustified.

"Since late Feb. 2013, 20.5 million cubic feet of methane gas has been removed," the spokesman told FoxNews.com. "Over the past 15 months, no methane has migrated into any of the homes in the area. Industrial-grade monitors have been installed in homes and have not recorded a single incident of methane or H2S incursion. No methane has been detected above ground in the community according to regular sampling by the La. Dept. of Environmental Quality."

Meanwhile, a YouTube video garnering nearly 7 million views since its posting in August shows the sinkhole, which is expected to at least double in size over time, swallowing numerous trees.

The video was reportedly shot by John Boudreaux, a local official coordinating efforts to hamstring the sinkhole’s growth, in hopes of attracting a measure of national attention to the affected residents’ plight.

And WAFB reports Gov. Bobby Jindal and Attorney General Buddy Caldwell announced their intention in early August to file a lawsuit against the Texas Brine Co. to recoup its estimated $8 million in expenses related to the state’s ongoing mitigation work.

The station also reported two weeks ago a “second” crack had been discovered in one of the numerous stabilizing berms installed around the sinkhole.

Texas Brine reportedly detected an increase in seismic activity on its instrumentation in the last few weeks, consisting primarily of "minor tremors or micro-earthquakes" (MEQs), although and not extended events or very long period (VLP) tremors.

Those MEQs ceased over a week ago, the company told FoxNews.com.

"Scientists agree that the seismic activity is a normal part of the process of the settlement/compaction going on in the deep geology," a Texas Brine spokesman said.

Mike Schaff is among those who have chosen to remain in his home, despite the rumblings.

“My wife lives in another part of the state. We were planning on retiring here," He told TheVerge.com. "Now, instead of coming up and enjoying the weekend, sitting on the patio drinking a few glasses of wine, we wake up in the morning and we go look for houses. That’s the new reality.”

For its part, Texas Brine had offered 92 buyout offers to local residents, and 68 had taken the deal as of July 31. And although numerous residents now receive weekly checks from the company in the amount of $875, many continue to pay their mortgages and utility bills in hopes of one day returning.

Editor's note: This story was updated Monday, Nov. 18, with comments from Texas Brine Co.