A light earthquake hit northern Oklahoma early Thursday and was felt in a radius of 160 kilometers including the city of Tulsa and the neighboring state of Kansas. The U.S. Geological Survey (USGS) said the magnitude-4.7 earthquake's epicenter was 13 kilometers southwest of Cherokee, Oklahoma at a depth of 6.2 kilometers. There were no immediate reports of major damage or injuries. The earthquake comes a month after a magnitude-4.5 temblor near the U.S. crude-oil hub of Cushing, Oklahoma. The earlier earthquake came only days after regulators imposed new rules for hydraulic fractural (fracking) disposal operations meant to prevent earthquakes in the area. Regulators ordered companies to shut or reduce usage of five saltwater disposal wells around the north-central Oklahoma city of Cushing. Saltwater, a normal byproduct of oil and natural-gas extraction work, is put into deep disposal wells that scientists say have contributed to a series of small and medium earthquakes in Oklahoma since 2009.
