USA Today: Oklahoma, a state more known for tornadoes than seismic shifts, is becoming all too familiar with earthquakes of late.
In the past seven days, 48 quakes larger than the magnitude of 2.5 have struck, says Paul Caruso, a geophysicist with the U.S. Geological Survey. In the past 30 days, there have been 157 quakes larger than magnitude 2.5.
"We've never seen anything like this in Oklahoma," he says.
The numbers back him up.
"Since 2009, the earthquake activity in Oklahoma has been approximately...