An earthquake hit outside of Oklahoma City on Saturday night. The magnitude 5.6 quake was the strongest in Oklahoma history. The US Geological Survey has released an initial report on the quake, but has not yet given an official cause.
In its coverage, the LA Times brought up the issue of hydraulic fracturing, or 'fracking,' as a potential cause. The paper referenced a study conducted by a research seismologist at the Oklahoma Geological Survey, examining the effect of hydraulic fracturing on seismic activity in a different part of the state. The study indicated that, for the moment, there isn't enough evidence to prove that fracking is at fault.
Texas experienced its own earthquake last month, a magnitude 4.8 shake near the Eagle Ford Shale deposit in South Texas. Here is KUT's initial coverage of the quake.
At the time of the South Texas quake, KUT News spoke with Cliff Frohlich, a seismologist and Senior Research Scientist at UT's Institute for Geophysics. He says it is incorrect to say that fracking causes earthquakes.
Instead, he told KUT News, "It isn’t the fracking that’s causing the quake. It’s when they drill a well and produce it some of the fracking fluids come back. They dispose of these fluids and it appears that the disposal of these fluids is causing the quakes, not the fracking.”
"Basically the procedure is you drill a well, then you frack the well, which means pumping the water in there. And then when they produce the well, some of the gas comes out, but some of the water comes back. It’s dirty water and you’ve got to get rid of it. And so in the Barnett Shale in the Fort Worth Basin, and in Arkansas, and elsewhere they pump the water back into the ground into a deep aquifer to get rid of it. And the quakes have been associated with the pumping of the water back into the ground, not the producing of the gas," Frohlich added.