LOSING GROUND - Louisiana Delta Sinking below the Waves.

This website describes the loss of a football-sized piece of ground every hour, 16 square miles every year... reclaimed by the Gulf of Mexico.  It is an interesting read.

Chrissy, we discussed this a while back and I just stumbled upon this web site today and it describes this process in detail.

http://projects.propublica.org/louisiana/

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Two years ago, NOAA removed 31 bays and other features from the Buras charts. Some had been named by French explorers in the 1700s.

The people who knew this land when it was rich with wildlife and dotted with Spanish- and French-speaking villages are getting old. They say their grandchildren don’t understand what has been lost.

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In the 1970s, up to 50 square miles of wetlands were disappearing each year in the areas with heaviest oil and gas drilling and dredging, bringing the Gulf within sight of many communities.

As the water expanded, people lived and worked on narrower and narrower slivers of land.

“There’s places where I had cattle pens, and built those pens … with a tractor that weighed 5,000 or 6,000 pounds,” said Earl Armstrong, a cattle rancher who grew on the river nine miles south of the nearest road. “Right now we run through there with airboats.”

Chrissy's thoughts about the land subsiding because of the digging of salt domes isn't far fetched. The loss of sediments is probably the largest factor for the land sinking, canals dug by the oil companies second, but thirdly, this article says

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Researchers eventually would show that the damage wasn’t due to surface activities alone. When all that oil and gas was removed from below some areas, the layers of earth far below compacted and sank. Studies have shown that coastal subsidence has been highest in some areas with the highest rates of extraction.

Maybe some of it has to do with the river and things being diverted for whatever reason....

Jake92 wrote:

Maybe some of it has to do with the river and things being diverted for whatever reason....

That is the biggest factor, Jake. Sediment used to flow down the river and settle out where the river met the Gulf. After the great flood of 1927 did this:

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Swollen by months of record rainfall across the watershed, the Mississippi broke through levees in 145 places, flooding the midsection of the country from Illinois to New Orleans. Some 27,000 square miles went under as much as 30 feet of water, destroying 130,000 homes, leaving 600,000 people homeless and killing 500.

Stunned by what was then the worst natural disaster in U.S. history, Congress passed the Flood Control Act of 1928, which ordered the U.S. Army Corps of Engineers to prevent such a flood from ever happening again. By the mid-1930s, the corps had done its job, putting the river in a straitjacket of levees.

But the project that made the river safe for the communities along the river would eventually squeeze the life out of the delta. The mud walls along the river sealed it off from the landscape sustained by its sediment. Without it, the sinking of land that only occurred during dry cycles would start, and never stop.

Eric I swear I have been following that for what 2-3 years now?

It creeps me out. I live on top of a salt dome and y'all ain't far from one.

And cracking into these things is dangerous as he'll

Chrissy* wrote:

Eric I swear I have been following that for what 2-3 years now?

It creeps me out. I live on top of a salt dome and y'all ain't far from one.

And cracking into these things is dangerous as he'll

The mining of the salt domes aren't causing the land above them to sink, though. Unless a dome collapses, and I don't think any have collapsed, the ground above them will remain undisturbed.

The drilling into a dome through a lake, as shown in Hallmarkgrad's video, was a freak occurrence. Water and dirt was sucked into the dome's void, but there was no mention of the dome's collapse.

There is speculation, however, that the many thousands of oil and gas wells extracting their products under the delta IS contributing to the sinking of the land.