This is chapter 21 of my book, Fever Rising. In the last chapter we explored the increasing sinkholes and how methane may be responsible. In this
chapter we take a closer look at the mother of all sinkholes, the Assumption Parish sinkhole in Louisiana. To see the first 20 chapters of the book,
here is a link to the last chapter where you'll find links to the other threads at the beginning of the thread
The reason for increasing sinkholes, land slips and land cracks
Chapter 21: A Closer Look at the Louisiana Bayou Corne Sinkhole
Of all the sinkholes, one remains the most infamous, the mother of all sinkholes…the Louisiana Bayou Corne Sinkhole. This massive 26-acre sinkhole,
turned bubbling methane gas lake, was created on August 3, 2012 in Assumption Parish, LA, after two months of minor seismic activity in the area.
The story below describes how NASA airborne radar detected that the land where the sinkhole exists slid 10 inches horizontally sometime in the year
prior to the collapse. Officials state that this is unusual for a sinkhole, claiming that land subsidence occurs in a vertical direction rather than
horizontally.
Most sinkholes are formed by natural processes, such as dissolved rock in the karst process, but the Bayou Corne sinkhole was human caused. According
to NASA, the Gulf Coast of Louisiana and eastern Texas sits on an ancient ocean floor with salt layers that form domes as the lower-density salt
rises. The Napoleonville Salt Dome underneath Bayou Corne extends to within 690 feet (210 meters) of the surface. Various companies mine caverns in
the dome by dissolving the salt to obtain brine and subsequently store fuels and salt water in the caverns. This particular collapsed mine was owned
by Occidental Petroleum and operated by Texas Brine.
The Bayou Corne sinkhole collapsed on August 3, 2012, creating a 1-acre lake that bubbled up natural gases and caused the evacuation of 350 residents
who lived within a mile of the collapse. Due to the obvious gases coming up from the sinkhole, officials worried that there could be a massive
explosion and they still worry to this day. Over the course of the next year, the sinkhole expanded to 25-acres swallowing up many trees along its
way. Here is an article from Livescience.com explaining the sinkhole and how the land slid 10 inches prior to the collapse.
Surprise: Louisiana Sinkhole Slid Sideways Before Collapsing
Livescience.com, Dec. 19, 2013
By Becky Oskin
The Earth's surface slid sideways by as much as 10 inches (26 centimeters) before collapsing into a still-growing toxic sinkhole in Bayou Corne,
La., a new study reports.
"This was unusual for us," said Cathleen Jones, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Usually at a sinkhole,
we expect to see vertical movement at the surface, some sort of subsidence," Jones said. "This horizontal motion is actually a new indicator people
should be aware of."
The Bayou Corne sinkhole sits in the Napoleonville salt dome, an upwelling of salt that was being mined for brine by injecting freshwater in wells and
extracting the dissolved salt. State officials and the U.S. Geological Survey (USGS) think the sinkhole appeared when an underground salt mine cavern
collapsed. Strong earthquake swarms starting June 8, 2012, preceded the sinkhole.
The study that revealed this information was published in the journal Geology, December 13. Jones said the cavern is a mile deep and the path between
the cavern collapse and the surface was a sideways flow that was like water slipping into a bathtub drain.
"The fact that the movement was toward a center point might tell you something about the geometry of the path that went down to the void," she said.
The subtle flow forms a pattern like a two-leafed clover, consistent with a cavern sidewall collapse as suspected by the USGS, Jones and NASA
colleague Ronald Blom report.
Jones also reported that the pit also opened into a natural underground oil reservoir, releasing toxic gases methane and hydrogen sulfide.
The Livescience.com article said the sinkhole emerged in a part of the Mississippi Delta where NASA tracks sinking called subsidence, which could help
improve levees. (The Earth's crust is sinking for a variety of reasons, including the massive weight of sediments delivered by the Mississippi
River.)
The article went on to say a plane equipped with a radar imaging system (called UAVSAR) regularly measures surface height in the Delta. The sensor
sends microwave energy pulses from the sensor on the aircraft to the ground, and can detect small changes over time.
Because the plane flew over Bayou Corne about once every year, the researchers can't say precisely when the Earth moved. But they do know that the
surface shifted after June 23, 2011, and before July 2, 2012. There was no surface movement before 2011.
As of early 2014, this environmental disaster grew into a 26-acre monster. Of the 65 families that lived nearby, 44 of them were bought out by Texas
Brine, while the others continued to collect an $865 per week check.
Geologists believe that the Bayou Corne sinkhole may still double in size to over 50 acres. Seismic activity and dangerous methane and hydrogen
sulfide gases continue to bubble up and release from the swamp. The hole is over 1,000 feet in depth. There is literally tons of methane gas migrating
through caverns throughout the area not to mention the hundreds of pipelines that crisscross carrying highly explosive chemicals. In January of 2014,
loud booms were reported around the same time as seismic activity about 45 miles from the hole and about 140 miles from BP’s Macondo Prospect oil
well in the Gulf of Mexico. These booms were most likely gas explosions as it escaped from fissures caused by minor earthquakes. With the dangerous
mix of gases, pipelines, and seismic activity, this is a catastrophe lurking in the not-to-distant future.
The sinkhole is believed to be caused by a failed cavern wall in the western-edge caverns under the Napoleonville Salt Dome. The collapse triggered a
chain-reaction of collapses, which continued to grow over the next year. Minor earthquakes that started on June 8, 2012, are the most likely culprit
of the original collapse. After that first quake two months prior to the collapse, tremors continued to rattle the area. What caused the earthquakes?
According to the lead Bayou Corne seismologist at the time of the collapse, Dr. Stephen Horton, the quakes were manmade, caused by the fossil fuel
industry. It was reported that within the first few months of the collapse, there were thousands of quakes with differing intensities.
Horton said that the Department of Natural Resources didn’t want to believe that the sinkholes caused the bubbles and that the bubbles are what
caused the sinkholes, rather than the quakes. He said that instead of calling the thousands of quakes that were occurring prior to the collapse what
they were, quakes, they called them tremors.
Horton pointed out that on July 24, 2012, the number of quakes drastically increased to hundreds, sometimes thousands a day until August 2 when they
stopped. The next day the sinkhole opened up.
Continued...