1.siIn March 2014, hydraulic fracturing – or fracking – caused 77 earthquakes in a small Ohio town that had no previous experience with seismic activity, according to a new study. One quake was large enough to be felt in neighboring areas. Fracking in Poland Township, Ohio was halted two days after the area was hit with a magnitude-3 earthquake along a hidden fault in rock which was deep beneath a natural gas well in the Utica Shale, according to research published in the Bulletin of the Seismological Society of America. The study’s authors said the magnitude-3 quake was “one the largest earthquakes ever induced by hydraulic fracturing in the United States.” All 77 quakes occurred between March 4-12, the study found. Besides the magnitude-3 quake, the study reported that most of the seismic activity was not felt by Poland Township’s population, which numbered 14,960 in the 2010 census. No previous seismic activity had occurred in Poland Township, which sits near the Pennsylvania border, and the quakes stopped once fracking operations were put on hold, according to lead study author Robert Skoumal, a graduate student in seismology at Miami University in Ohio. More