"The 585 earthquakes that Oklahoma had in 2014 was a lot. But this year, Oklahoma has had more than that in less than nine months.
About 20 minutes before midnight Monday, Oklahoma topped last year's total with its 586th earthquake of magnitude 3 or greater. Oklahoma Geological Survey (OGS) data indicate that a magnitude-3.3 quake about 20 miles east of Enid was the one that broke the record.
The state has averaged 2.5 quakes a day in 2015. If that rate continues, Oklahoma would have more than 912 quakes this year."
Mike Soraghan reports for EnergyWire August 19, 2015.
Source: EnergyWire, 08/20/2015