Is Vermilion Parish Sinking Into the Gulf of Mexico?

It is no secret. Louisiana’s coastline is disappearing. What many scientists are not 100 percent sure about is why. One explanation that is not getting much attention could be because of active geologic faults that run along the coast of Louisiana.
Over the years, the coastline is shrinking and the shoreline is slowly creeping into the Gulf of Mexico. In recent years, studies of subsurface faults, salt domes and other geologic characteristics have emerged as critical in the debate over what is causing Louisiana to lose vast tracts of land. The coast has lost about 1,900 square miles of wetlands -- an area about the size of Delaware -- since the 1930s.
There are many theories as to why.
Some are blaming it on the oil and gas industry; others say it is saltwater intrusion that is destroying vegetation that have protected the land. But one theory that is getting little attention as why the land is disappearing could be a natural occurrence.
Kathy Haggar, a geologist who lives in Baton Rouge, spoke about geologic faults to the Abbeville Rotarians on Wednesday.
She explained to the Rotarians about her theory as to why there is more flooding along the coast than ever before.
Her answer is simple: Louisiana is sinking into the Gulf of Mexico because of geologic faults along the coastline.
“All those faults together are acting to lower south Louisiana over time,” Haggar said. “When they move, they make an adjustment. All these faults act together to lower south Louisiana.”
She explained to the Rotarians she has been studying a wetlands area called “Goose Point” along the northern part of Lake Pontchartrain. At one time, Goose Point, located near Mandeville, was a 600 acre freshwater marshland. Today, because of saltwater intrusion, the marshland is brackish and lakes that were small lakes, are getting wider and wider.
Haggar told Rotarians there has never been oil field drilling at Goose Point but yet the marshland is slowly seeing more and more saltwater, killing vegetation.
“Why is the marsh disappearing at Goose Point?” Haggar asked. She pointed out there is a large fault below Goose Point.
She also showed pictures of how far the coastline extended out into the Gulf of Mexico 6,000 years ago and how it slowly moved inward over time to where it is today.
Today, Haggar said, because of levees created to stop the natural flow of the Mississippi River and the lack of sediment coming from the river, which was once used to replenish the deltas and marshlands west of the Mississippi River, the land has not been able to rebuild like it has over thousands of years prior to man’s involvement. Because there is no rebuilding of the marshland, coupled and the slow rise in the sea level, and the movement is geologic faults, it is causing the land to slowly sink.
Geological Society of America’s Geology journal, charts a major fault, the Michoud fault, that runs through eastern New Orleans. The slumping of the Michoud fault, a study said, has caused as much as about 73 percent of the subsidence in sections of eastern New Orleans, an area that has seen some of the worst rates of land loss in south Louisiana. The land sank by as much as 1.7 inches from 1969 to 1971, according to Roy Dokka, a Louisiana State University geologist.
There are about a dozen small faults just in Vermilion Parish. If the sinking is caused by natural tectonic fault movement, then all of the money in the world won’t stop land from sinking, Haggar said.