"The number of earthquakes in Oklahoma is increasing with 226 magnitude 3.0 earthquakes occurring as of last week in the state just this year, Oklahoma is having more 3.0 magnitude earthquakes than the Western U.S. combined. The majority of them are occurring in central Oklahoma," Austin Holland research seismologist with the Oklahoma Geological Survey Edmond Sun
USGS scientists have found that at some locations the increase in seismicity coincides with the injection of wastewater in deep disposal wells. Much of this wastewater is a byproduct of oil and gas production and is routinely disposed of by injection into wells specifically designed for this purpose.