In a state where residents regularly brace themselves for tornados, Oklahomans now have another disturbing hazard to watch out for: earthquakes. In recent years, there’s been a steady and worrying uptick in quake activity with almost 3,000 quakes in 2013—the state’s most seismically active year ever. As rattled Oklahomans eye the ground warily, researchers and environmentalists say that fracking and other oil and gas extraction techniques are likely to blame for the recent quakes.
In October, the U.S. Geological Survey reported that fracking and its wastewater disposal methods could be linked to the over tenfold increase in Oklahoma’s earthquake activity since 2009. The controversial drilling practice involves injecting massive amounts of wastewater deep into the ground, which increases pressure along fault lines and makes them more susceptible to rupture.
Research also warns that fracking may have been the reason behind a magnitude 5.7 quake in November 2011–the largest earthquake ever recorded in the state–that damaged 14 homes and injured two people. Though many of the quakes are mostly minor and register around magnitude 3.0, the yearly average for earthquakes has been rising to about 40 per year since 2008.
Seismic swarms have also rippled across parts of the country in similar toxic wastewater disposal sites, where nearby faults become overloaded by fracking’s high-pressure injections. Although research has shown a high correlation between earthquakes and fracking’s wastewater wells, scientists and regulators still lack the necessary proof to back new laws to protect residents. In the meantime, worried Oklahomans are starting to turn to earthquake insurance.
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