Washington — Seismologists are warning that Oklahoma’s skyrocketing earthquakes linked to oil and gas activity are liable to get stronger and more dangerous.
Oklahoma has seen a 50 percent rise in earthquakes since October of last year. Since 2009, after the nation’s fracking boom began, the earthquake activity in Oklahoma has been approximately 40 times higher than in the 30 previous years, according to the U.S. Geological Survey.
The recent surge in the rate of the quakes has prompted the USGS and the Oklahoma Geological Survey to issue a warning that the earthquakes could get stronger, with the agencies saying there is a significantly increased chance for a damaging magnitude 5.5 or greater quake in central Oklahoma.
“While it’s been known for decades that Oklahoma is earthquake country, we hope that this new advisory of increased hazard will become a crucial consideration in earthquake preparedness for residents, schools and businesses in the area,” said Bill Leith, senior science advisor at the USGS.
A USGS analysis suggests a likely contributing factor to the increase in earthquakes is drilling wastewater injected into deep geologic formations.
Fracking produces large amounts of wastewater, which companies often pump deep underground as an economical way to dispose of it without contaminating fresh water. Injection raises the underground pressure and can effectively lubricate fault lines, weakening them and causing quakes, according to the USGS.
Most ofthe Oklahoma quakes have been small so far. But scientists have linked a 5.7 magnitude quake near Prague, Oklahoma in 2011 to disposal of drilling wastewater. That earthquake was felt as far away as Milwaukee and destroyed 14 homes.
The Oklahoma Geological Survey disputes the link of that earthquake to oil and gas activities, though, and is not joining the USGS in attributing the skyrtocketing rate of earthquakes to disposal of drilling waste. The USGS has also linked quakes in Arkansas, Ohio, Texas, and Colorado to oil and gas activities. Scientists are studying whether a recent surge in earthquakes in Kansas is also attributate to the uptick in fracking there.