A new study links the March 2014 earthquakes in Poland Township, OH to hydraulic fracturing.  The fracking activated a previously unknown fault.  The quake had a magnitude of 3.0.  The study was published online by the Bulletin of the Seismological Society of America (BSSA).

In March 2014, a series of five recorded earthquakes, ranging from magnitude 2.1 to 3.0, occurred within one kilometer (0.6 miles) of a group of oil and gas wells operated by Hilcorp Energy, which was conducting active hydraulic fracturing operations at the time. Due to the proximity of a magnitude 3.0 event near a well, the Ohio Department of Natural Resources (ODNR) halted operations at the Hilcorp well on March 10, 2014.

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Hydraulic fracturing, or fracking, is a method to extract natural gas and oil from shale rock by injecting a high pressure solution into the rock formation.  The high pressure fractures the rock and releases the gas and oil.  It has come under quite a bit of criticism lately.  This is not the first time that it has been determined to be the cause of an earthquake.  It has also been implicated in other environmental problems, like contaminated ground and surface water and air pollution.