Seismic activity in shale-rich Oklahoma was apparent again, with the U.S. Geological Survey recording three minor events in less than 24 hours as of Monday. Three tremors of magnitude-3 or less were recorded in Oklahoma since Sunday. A magnitude-2.8 tremor was reported Sunday in Kansas about six miles from the northern border of Oklahoma. The state reported one of its largest earthquakes in recorded history with a mid-February magnitude-5.1 earthquake near Fairview, about 100 miles north of Oklahoma City. The USGS reported last year the increase in seismic activity in Oklahoma since 2009 may be in part related to activity associated with oil production. The agency said the disposal by the energy industry of wastewater […]