Shale-rich Oklahoma experienced more than a dozen seismic events in the five days ending Friday, data from the U.S. Geological Survey show. A magnitude-2.7 tremor was reported shortly after midnight local time Friday near the north-central town of Enid. The largest of the 16 seismic events since Monday was a magnitude-3.6 quake reported Wednesday in north-central Alva. Several towns in and around the region recorded more than one quake in the last week. On Wednesday, after the USGS recorded 9 recent events in the Blanchard area, the Oklahoma Corporation Commission’s Oil and Gas Division said it was investigating all of the oil and gas activity in the area. State researchers said wastewater injection, not from hydraulic fracturing operations […]