The possibility of an early-warning system stems from new NASA research into a monstrous sinkhole that opened in Louisiana in 2012, forcing the evacuation of hundreds of residents.
Two NASA researchers examined radar images of the sinkhole area near Bayou Corne, La. Cathleen Jones and Ron Blom discovered that the ground near Bayou Corne began shifting at least a month before the sinkhole formed — as much as 10 inches toward where the sinkhole started. Since its formation, the sinkhole has expanded to 25 acres and is still growing.
The NASA findings raise the possibility that engineers eventually could develop a way to predict the location of sinkholes. It would require the constant collection and monitoring of the Earth’s surface with radar data collected from planes or satellites.
“It’s not a magic bullet,” Blom said. But it could be “one more tool in a tool kit.”
The radar images studied by the two NASA scientists were part of the agency’s ongoing effort to monitor the Louisiana coast, which is rapidly sinking into the Gulf of Mexico. Although the Louisiana images were taken from a research jet, the scientists said a satellite with similar technology could do the same job.
And though such a system wouldn’t be cheap — the price of building and launching a satellite usually is in the hundreds of millions of dollars — the gains could be significant. In Florida alone, sinkholes cause about that much property damage each year.
Although there are no recent state data on sinkhole damage, a 2010 report by the Florida Office of Insurance Regulation estimated that sinkholes each year cost the state $200 million to $400 million.
Thousands of claims related to sinkholes were made and closed in recent years. In 2009 alone, there were about 4,700 closed claims and 2,600 open claims, according to the report. The majority of claims tallied by state officials were from three counties — Hernando, Pasco and Hillsborough along Florida’s west coast — though Orange and Polk were in the top 10 statewide from 2006 to 2010.
In one high-profile case last year, a sinkhole wrecked villas at Summer Bay Resort near Walt Disney World, forcing residents to evacuate.
There’s a human cost, too. Even though sinkhole deaths are rare, a Hillsborough County man was killed last year when a sinkhole formed beneath his house.
The prevalence of sinkholes in Florida can be attributed to the state’s geology.
Sinkholes are most commonly found in areas where the underlying rock can easily be dissolved by groundwater. Once eroded, the surface then can collapse into underground caves and other spaces. Florida, with its wet climate and porous limestone beneath the surface, is particularly susceptible to this type of natural disaster.
Aware of the dangers, Florida officials also are taking steps to detect sinkholes.
Last year, state geologists began a three-year, $1 million project to identify which areas in Florida are most conducive to sinkhole formation. They’ve begun by surveying three northern Florida counties — Columbia, Hamilton and Suwannee — with the goal of creating a statewide “rating of vulnerability for sinkhole formation,” said Clint Kromhout, a geologist with the Florida Geological Survey.
The hope, he added, is to give emergency officials more information to help “mitigate against potential loss of property and life during sinkhole formation,” he said.
Although property owners have limited options when faced with a sinkhole — other than to evacuate — state officials said knowing more about vulnerable areas could help homebuilders and local governments avoid sinkholes when planning developments.
“One of the most important things we can do, and one of the more effective things we can do, is educate the public about the risks,” said Aaron Gallaher, a spokesman for the Florida Division of Emergency Management.
©2014 The Orlando Sentinel (Orlando, Fla.)
