Assumption Parish, Louisiana sinkhole — Videos
Louisiana Sinkhole Crisis is Out of Control — GET OUT of Southern Louisiana
BAYOU CORNE, La. — The Assumption Parish sinkhole is a lot like a living, breathing thing. More than 200 days after it mysteriously started swallowing up the swamp, hundreds of residents are still under a mandatory evacuation order. Geophysicists say the cavern that caused the sinkhole at the surface is still collapsing, leaving Bayou Corne residents wondering if there will ever be an end in sight. Geophyisicists now say the western side of one of the brine caverns is collapsing, filling in from deep in the Earth, causing the sinkhole at the surface to expand and contract.
One of those questions: What caused the cavern to collapse? “The sinkhole is constantly changing. It changes every time we go out there. Not just on the surface, but in the sub-surface,” said Gary Hecox, a hydrogeologist with CB&I, formerly the Shaw Group, who is a consultant for the state about how to best handle the sinkhole.
He said it’s uncharted territory. “The cavern was 3,400 feet deep, which is deeper than any known cavern failure impacting the surface in the international record,” Hecox said.
Nowhere in the world has a brine cavern this large collapsed, and Hecox said the data shows it’s not finished yet. “We still have 450 feet to fill. How long is it gonna take to fill this up? At one foot per day, we’re still looking at an event that’s gonna run over a year,” he said.
Every time it shifts, recently installed seismic monitors pick up tremors like little earthquakes. When it does, big bubbles of natural gas, vegetation and crude oil are released to the surface. They call it a “burp”. “It appears that the sand and gravel that’s in the bottom of the sinkhole breaks up a large gas bubble into many small bubbles just like an aquarium,” Hecox continued, “That is a good thing. Because if you get a single bubble up and have an ignition source you can have a flash over.” A flash over is an explosion, like the kind you can see if you leave the gas on too long before lighting a propane grill. But Hecox said a large natural gas bubble from the sinkhole lit by any ignition source could mean major damage on the surface. Instead those little bubbles are coming out all around the actual sinkhole site in the form of bubble sites in the bayou. Twenty new bubble sites have been spotted in the last month.
In recent weeks, some of the residents who stayed behind, and are living in the area at their own risk, noticed some problems that are typically invisible to the naked eye.
Bubble sites popped up in neighborhoods that are typically dry during flooding after a recent rain storm. It caused Wilma Subra, a chemist with the Louisiana Environmental Action Network, to raise a red flag with the Louisiana Department of Environmental Quality.” A house acts like a tent. So, if it’s migrating up through the soil, and it’s being caught in the house, it’s building up concentrations in the house. And then if it reaches explosive level, then one little spark in the house would set it off,” Subra said.
Many feel forgotten, Weber said. Especially by Gov. Bobby Jindal. The governor has yet to visit the sinkhole site or publicly talk about it. “He’s promoting plants around the area, chemical plants. And he was in the area and he wouldn’t, still to this day does not acknowledge it,” Weber said.
In October and November of 2012, Jindal announced two chemical plant expansions a few miles from Bayou Corne, one in nearby Geismar and one in Donaldsonville.
But in six months, he’s made no visit to the sinkhole site. “Where is he? Where is Jindal? He’s all over the United States, but he can’t come forty minutes south of Baton Rouge and visit,” Weber asked.
As photos from the Louisiana Environmental Action Network show, when the sinkhole first appeared, it was just 400 feet in diameter. As of mid-February, it had swallowed nine acres.
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