California is no longer the earthquake capital of the contiguous U.S., and even earthquake capital Alaska has been surpassed by an unlikely new contender, according to a new report.
That new capital is Oklahoma. Before 2009, the Sooner state was barely on the map, according to stats provided by the United States Geological Survey.
According to the Center for Investigative Reporting's study:
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.
CIR's report found Kansas, Texas, Ohio and Colorado all had major upswings in seismic activity in recent years.
Citing studies, CIR says the increased amount of hydraulic fracturing — or fracking — of oil wells in those states is playing a significant role in causing the quakes.
It's not the drilling itself, these studies found, that causes the seismic activity. Instead, it appears to be the large underground wastewater ditches that form as a result of the oil-extraction technique.
You can read their full report on CIR's website. And if you're curious about the locations and magnitude of the many earthquakes California experiences each year, you can see that data in our Earthquake Tracker tool.