Oklahoma recorded more than three times as many earthquakes as California in 2014 and remains well ahead in 2015. Data from the U.S. Geological Survey shows that Oklahoma had 562 earthquakes of magnitude 3.0 or greater in 2014; California had 180. As of Jan. 31, Oklahoma recorded 76 earthquakes of that magnitude, compared with California’s 10.
According to the Advanced National Seismic System global catalog, in 2014, Oklahoma even beat Alaska, the nation’s perennial leader in total earthquakes, though many small events in remote areas go unrecorded there.
In California, earthquakes always have been relatively common, but in Oklahoma, they were much more rare – at least until 2009. ... Numerous studies agree that wastewater disposal from hydraulic fracturing, or fracking, is a major factor in increasing seismic activity. ... The areas facing new earthquakes share a significant burst of drilling activity and pre-existing geologic faults. Heavily drilled areas such as North Dakota’s Bakken formation, which aren’t located near faults, have not seen the same increase in earthquakes.
