By Philip Ross
When the earth below Bayou Corne, La., collapsed on Aug. 3, 2012, it created a hole nearly 750 feet deep and covered nearly 15 acres. The sinkhole caused a flurry of bad publicity for Texas Brine Co., whose operations in Bayou Corne caused the underground salt dome cavern to collapse and resulted in a class-action lawsuit for the hundreds of nearby residents who were evacuated. Now, evidence suggests that NASA radar may have inadvertently spotted the sinkhole before it occurred.
Researchers from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., analyzed data acquired by the agency’s Uninhabited Airborne Vehicle Synthetic Aperture Radar, or UAVSAR, system in 2012. UAVSAR uses radio waves to gather information about features on Earth’s surface. Researchers looked specifically at the ground where the giant Bayou Corne sinkhole formed and examined radar scans from a month and a year before the ground collapsed.
Their study, published in the journal Geology, found that over that time, the ground surface layer had moved as much as 10 inches toward the sinkhole’s center.
“Our work shows radar remote sensing could offer a monitoring technique for identifying at least some sinkholes before their surface collapse, and could be of particular use to the petroleum industry for monitoring operations in salt domes,” Ron Blom, a NASA analysts and co-author of the study, said in a statement. “Salt domes are dome-shaped structures in sedimentary rocks that form where large masses of salt are forced upward. By measuring strain on Earth’s surface, this capability can reduce risks and provide quantitative information that can be used to predict a sinkhole’s size and growth rate.”