The U.S Geological Survey recorded a cluster of tremors early Friday in a part of Oklahoma on a watch list for activity related to shale oil and gas operations. Four tremors were reported as of 5:45 a.m. EDT by the USGS, the largest of which was a magnitude-3.3 event about three miles outside the town of Edmond. At least eight quakes were recorded Thursday , with Edmond experiencing a magnitude-4.2 event. One of the U.S. states with a significant amount of shale oil and natural gas, a study from the USGS found the disposal of oil and gas-related wastewater is the “primary reason” for an increase in seismic activity in central states like Oklahoma. That process is different […]