Oklahoma suffers more earthquakes than any other non-Western state, study finds
Oklahoma, the home state of new Environmental Protection Agency head Scott Pruitt, suffers more natural and man-made earthquakes than any other state in the central and eastern United States.
The state endured more large earthquakes in 2016 than in any previously recorded year, according to a study released Wednesday by the U.S. Geological Survey on natural and induced earthquakes. “Prior to 2008, Oklahoma typically experienced about two events per year at a magnitude of 2.7,” Mark Petersen, chief of the USGS National Seismic Hazard Mapping Project, said in a press call. “However, over the past few years, several thousand of these earthquakes occurred.”
Since 2008, states across the central and eastern United States have seen the number and frequency of their natural and man-made earthquakes rise “hundreds of times,” Petersen said in a statement. Man-made earthquakes are primarily caused by wastewater disposal, a process where water from oil and gas operations is injected into deep underground wells. That weakens fault lines, which can then trigger earthquakes. Additionally, fracking, in which liquids are injected at high pressure into subterranean rock, can lead to earthquakes.
Oklahoma has been hit hardest; its seismic risk now rivals California’s, the study found. The state also experienced its largest-ever recorded earthquake this year, when the town of Pawnee was struck by a quake measuring 5.8 on the Richter scale.
Though USGS scientists reported that humans were causing earthquakes in 2013, Oklahoma didn’t acknowledge it until 2015. Pruitt’s silence on the issue, his multiple lawsuits against the EPA while he was Oklahoma attorney general, and his close relationship to the oil industry have environmental activists extremely worried about his leadership of the EPA. The Sierra Club launched an earthquake-related ad urging senators to vote against Pruitt’s confirmation.
“As the costs of earthquake damage pile up, and the U.S. Environmental Protection Agency and U.S. Geological Survey have urged action, Pruitt has done nothing as families have been forced from their homes,” said a statement announcing the ad’s release.
The USGS study did have some good news for Oklahomans: The overall number of earthquakes fell from 4,000 in 2015 to 2,500 in 2016.
Both natural and induced earthquakes decreased across the region, the USGS report found. And while the 2016 report found that 7 million people lived in areas that faced the potential for damaging man-made earthquakes, that number dropped by almost half in the 2017 report. That’s largely thanks to the fact that no earthquakes occurred in the heavily populated Dallas-Fort Worth area, USGS researchers said in the press call. Though researchers weren’t sure exactly why earthquakes dropped so much in that region, they said fewer wastewater injections likely contributed.
“I feel this is a success story,” Petersen said, “in how we can reduce the seismic hazard.”