Four small earthquakes were recorded Monday in Oklahoma, with the strongest a 4.7-magnitude one felt throughout much of the central U.S. state and into neighboring Kansas. There were no immediate reports of damage. The U.S. Geological Survey (USGS) said the strongest earthquake hit early Monday about 26 kilometers west of Medford, or about 130 kilometers south of Wichita, Kansas. A 3.0-magnitude earthquake struck just outside Oklahoma City 90 minutes later, a 3.1-magnitude earthquake was recorded an hour after that near Perry, and a 3.2-magnitude earthquake struck at midday near Cherokee. Another 4.7-magnitude earthquake hit northern Oklahoma on November 19, prompting state regulators to shut down some oil and natural-gas wastewater disposal wells in the area and reduce the volume at others. Earthquakes were rare in Oklahoma until the recent boom in oil and natural-gas drilling using the hydraulic fracturing (fracking) technique.
