Fracking Operations Cause Thousands of Earthquakes in Arkansas

We talked last month about hydraulic fracturing (‘fracking’) of rocks to release deep pockets of trapped oil, and mentioned the dangers. Three days ago, on Thursday 28 July 2011, Mike Ludwig posted an alarming report on the American site, Truthout. On the previous day, the Arkansas Oil and Gas Commission placed a ban on fracking wastewater wells in the area. A sudden change of heart? Er, not exactly. The uncomfortable fact was, fracking wastewater disposal wells in central Arkansas had caused more than 1,200 minor earthquakes of up to 4.7 in magnitude. Fracking produces millions of gallons of highly polluted wastewater, and the gas industry has been experimenting with different ways to dispose of it.

Mike Ludwig reported: ‘At least three gas companies were injecting fracking wastewater in the area of the earthquake outbreak, including BHP Billiton Petroleum, Clarita Operating LLC and Chesapeake Operating. The companies were injecting fracking wastewater near an active fault.’ He continued, ‘Steve Horton, an earthquake expert from the University of Memphis, told Truthout that continued fracking activity near the fault could have caused an earthquake strong enough to cause property damage. At least one resident in the area is suing the gas companies over damage an earthquake caused to his home.

‘Scott Ausbrooks of the Arkansas Geological Survey said a network of cracks and joints in underground rock formations allowed the fracking fluids to reach the fault and cause earthquakes. The earthquakes began rumbling through the countryside after the injections began.’

In the few days since a moratorium on drilling has been declared, the number of earthquakes has dropped by two-thirds.