Man-made earthquakesOklahoma rejects “rush to judgment” on the connection between fracking and earthquakes

Published 10 February 2015

Between 1978 to mid-2009, Oklahoma recorded one or two 3.0 or greater magnitude earthquakes. Last year the state experienced 585 earthquakes of 3.0 magnitude or greater. Studies conducted by seismologists, including those who work with the United States Geological Survey(USGS), have attributed the spike in earthquakes to the roughly 3,200 active disposal wells, in which wastewater produced during oil and gas drilling is stored deep underground, and independent scientific studies have established the causal relationship between fracking and earthquake. Arkansas, Ohio, and Colorado have imposed temporary restrictions on fracking, while Texas and Illinois are considering similar measures – but the Oklahoma Geological Survey says that “We consider a rush to judgment about earthquakes being triggered to be harmful to state, public and industry interests.”

Between 1978 to mid-2009, Oklahoma recorded one or two 3.0 or greater magnitude earthquakes. Last year the state experienced 585 earthquakes of 3.0 magnitude or greater. Studies conducted by seismologists, including those who work with the United States Geological Survey (USGS), have attributed the spike in earthquakes to the roughly 3,200 active disposal wells, in which wastewater produced during oil and gas drilling is stored deep underground.

The Tulsa World reports that Oklahoma’s energy boom began in 2010, when new horizontal drilling and fracking techniques opened up exploration in the Mississippian lime play in northern Oklahoma and southern Kansas. Up to ten barrels of wastewater, a salty mix of chemicals used in the extraction process and disposed of by injecting it back into the ground, accompany every barrel of oil.

State agencies have insisted that more studies are needed before connecting the increase in earthquakes to fracking. “At this point in time, I don’t think we have enough information to truly understand what is causing earthquakes,” Governor Mary Fallin told the Tulsa World. “We know a lot of it’s just natural earthquakes that have occurred since the beginning of the earth, but there has been some question about disposal wells.”

The Oil and Gas industry echoes Fallin’s response. “I think it’s unwise to come to any final conclusions either way, and I think many of my member companies would say that, as well,” said A.J. Ferate, vice president of regulatory affairs for the Oklahoma Independent Petroleum Association.

Oklahoma State University geology professor Todd Halihan, disagrees with the state’s official position on the spike in earthquakes. “It’s funny because sometimes I think I’m doing discussions about climate change, because it’s all the same thing,” he says. “In terms of the peer-reviewed data sets, I don’t know of a paper that’s not attributing our seismicity to injection.”

While only a small portion of the nation’s injection wells have been identified as possibly causing earthquakes, Arkansas and Ohio, along with several cities in Colorado, have temporary prohibited fracking due to their connection to earthquakes. Lawmakers in Oklahoma, on the other hand, have proposed bills that would block cities from issuing measures to ban fracking.

In an investigation on how fracking-related earthquakes have affected state residents, the Tulsa World discovers that while many residents are concerned about the spike in earthquakes, they also see the economic benefits. The city of Medford, home to a large natural gas storage facility and an oil refinery, has benefitted from the tax revenue and jobs the energy industry has brought to the area.

“We’ve gotten so used to them (earthquakes) that usually we just look at each other and say, ‘Well, that was a big one,’” said Barbara Bush, the city clerk of Medford. She added that “With all the shaking that’s going on — the water lines are old, the gas lines are old. … That’s what really worries me.”

Grant County, where Medford holds the county seat, experienced 1,071 earthquakes of all magnitudes last year. “I think most people have come to the conclusion that it’s related to the oil activity,” Bush said. “There’s been oil booms and oil activity around here for years, but we haven’t had earthquakes. But we haven’t had all the saltwater injection wells this close, either.”

The Oklahoma Geological Survey, the agency charged with investigating the state’s earthquakes, has yet to publish an explanation for the surge in earthquakes. “We consider a rush to judgment about earthquakes being triggered to be harmful to state, public and industry interests,” reads a statement on the agency’s Web site. The Environmental Protection Agency, however, recommends that the state “Take early prudent action to minimize the potential for injection‐induced seismicity rather than requiring substantial proof of the causal relationship.”

USGS research geologist Bill Ellsworth believes Oklahoma’s sudden increase in earthquake activity is clear. “We are virtually certain that almost everything that we are seeing in terms of increased seismicity not only in Oklahoma but in Texas are all related to recent changes in the way that oil and gas are being produced. Scientifically I don’t think there’s really a lot of doubt about that.”