The rate of earthquakes in Oklahoma has increased by about 50% since October 2013, significantly increasing the chance for a damaging quake in central Oklahoma.
In a new joint statement by the USGS and Oklahoma Geological Survey, the agencies reported that 183 earthquakes of magnitude 3.0 or greater occurred in Oklahoma from October 2013 through April 14, 2014. This compares with a long-term average from 1978 to 2008 of only two magnitude 3.0 or larger earthquakes per year.
The joint statement indicates that a likely contributing factor to the increase in earthquakes is wastewater disposal by injection into deep geologic formations and not due to typical, random fluctuations in natural seismicity rates. Much of this wastewater is a byproduct of oil and gas production.