Oklahoma has experienced more earthquakes at magnitude 2.0 or higher this year than California. CoreLogic staffer Maiclaire Bolton takes a look at the increase seismic activity in Oklahoma and surrounding areas which correlates with the oil and gas exploration there.
The U.S. Geological Survey (USGS) did a study this year to observe the increased activity, developing a short term view of earthquake hazards as they relate to induced (man-made) seismic activity:
Using data from the USGS, Figure 3 shows the rapid change in the rate of earthquakes in Oklahoma compared to California since 1970...On the other hand, Oklahoma experienced very low earthquake activity until 2009 when the rate began to rapidly increase. This increase is believed to correlate with increased oil and gas activity, specifically the pumping of waste water at fluid injection wells