Oklahoma Seismicity Back in the News- after a good, long respite

Although seismicity in Oklahoma has waned considerably in the past couple of years, a M 4.5 earthquake occurred on Monday, January 31st near Medford, Oklahoma. The seismic event and its aftershocks were felt across most of Oklahoma and parts of Kansas. Two aftershocks were recorded shortly after the initial event, one M 2.1 event near Renfrow and a M 2.5 event near Medford. While the M 4.5 originated at an estimated depth of about 7.8 km, the two aftershocks were much shallower, at 0 km and 2.5 km, respectively.

The Oklahoma Corporation Commission (OCC) has announced that it would shut-in deep saltwater disposal wells and restrict others in proximity to the earthquake: 3 disposal wells within 6 miles of the epicenter will be shut-in and all other disposal wells within 10 miles of the epicenter will be restricted to an average daily volume of 500 bbls.

The OCC has previously shut-in wells near Medford due to increases in seismicity. The measures taken by the OCC have contributed greatly to the decrease in injection-induced seismicity in Oklahoma.?