Now, the USGS has produced a 2016 seismic hazard forecast which includes natural as well as fracking-induced earthquakes. In it, they warn that injection of water can induce earthquakes of larger magnitudes, particularly if there are nearby pre-existing faults reactivated by upsetting subsurface pressure.
“Near some areas of active induced earthquakes, hazard is higher than in the 2014 USGS National Seismic Hazard Model (NHSM) by more than a factor of 3; the 2014 NHSM did not consider induced earthquakes,” the report states.
The USGS warns that if the fracking-induced seismicity continues unabated, areas in Kansas and Oklahoma may face similarly damaging earthquakes as those seen in California.
“Conversion of ground shaking to seismic intensity indicates that some places in Oklahoma, Kansas, Colorado, New Mexico, Texas, and Arkansas may experience damage if the induced seismicity continues unabated,” the report warns. “The chance of having Modified Mercalli Intensity (MMI) VI or greater (damaging earthquake shaking) is 5–12 percent per year in north-central Oklahoma and southern Kansas, similar to the chance of damage caused by natural earthquakes at sites in parts of California.”
Oklahoma state officials confirmed on Tuesday that 17 fossil-fuel extraction wastewater disposal wells in northeastern Oklahoma had been shut down after the weekend earthquake. The Oklahoma Corporation Commission (OCC) ordered the closing of 37 additional wells in a 514-square-mile area near the quake’s epicenter.
Underground deposits of wastewater, from natural gas and oil production, and the controversial practice of hydraulic fracturing, or "fracking" in particular, have been linked to an increase in earthquakes in Oklahoma, but regional EPA spokesman Joe Hubbard has not commented on the amount of wastewater present in the 17 closed wells, or given a reason why the wells were closed. The OCC has been asking the owners of wastewater wells to to dial back their waste since 2013.