NASA Finds Glacial Sediments Adding to Louisiana Coast’s Sinking
A study by NASA and Louisiana State University scientists finds that sediments deposited into the Mississippi River Delta thousands of years ago when North America’s glaciers retreated are contributing to the ongoing sinking of Louisiana’s coastline. The weight of these sediments is causing a large section of Earth’s crust to sag at a rate of 0.1 to 0.8 centimeters (0.04 to 0.3 inches) a year.

The sediments pose a particular challenge for New Orleans, causing it to sink irreversibly at a rate of about 0.4 centimeters (0.17 inches) a year, according to data from a network of global positioning system stations and a model of sediment data collected from the northern Gulf of Mexico and the Mississippi Delta.

Hurricanes Katrina and Rita in 2005 focused national attention on the Gulf coast’s vulnerability to hurricanes due to loss of wetlands and sea level rise. These new findings add another factor for scientists, government agencies and the public to consider when assessing the vulnerability of the region to hurricanes and large storms.