The news follows the realization that 2012 radar data indicated the location of a massive depression before it collapsed in Louisiana, swallowing 25 acres of land.
Describing the finding in the February issue of Geology, researchers said analyses of the data revealed that the ground surface layer in Bayou Corne, La., became drastically deformed at least a month before the collapse in August 2012. Interferometric synthetic aperture radar (InSAR) imagery obtained in June 2011 and July 2012 by one of the agency's jets showed that before the ground gave way, it rose 10 inches higher than the land around it -- a possible harbinger of impending collapse.
"While horizontal surface deformations had not previously been considered a signature of sinkholes, the new study shows they can precede sinkhole formation well in advance," lead researcher Cathleen Jones of NASA's Jet Propulsion Laboratory said in a written statement. "This kind of movement may be more common than previously thought, particularly in areas with loose soil near the surface."
Though researchers are optimistic that radar imagery could pinpoint subtle land deformations, those changes may not be an identifying factor for every sinkhole. That's why routine flyovers to obtain radar data may be more costly than they're worth.
Still, the technique could be useful in specific situations.
Since its collapse in 2012, the Louisiana sinkhole has continued to grow, forcing longtime residents to flee their homes. Researchers cannot stop the depression from growing, but they may be able to predict the direction of the sinkhole's next expansion by tracking surface deformations.