The recent U.S. drilling boom is almost certainly causing earthquakes; that’s the conclusion of a growing number of reports including a recent study from the U.S. Geological Survey. Although the earthquakes have been minor so far, scientists warn that disturbing the ancient faults could set off a much larger disaster.
According to the AP, the earthquakes are mostly caused by companies injecting wastewater deep underground, activating dormant faults. A few of the quakes are also caused by hydraulic fracturing, where companies pump a combination of water, sand and other chemicals into rock formations to free up gas and oil.
Up until now, the oil and gas industry has said more research was required to prove a connection between the earthquake swarms and new drilling.
The U.S. Geographical Survey report says that eight states have been affected by small drilling earthquakes: Alabama, Arkansas, Colorado, Kansas, New Mexico, Ohio, Oklahoma and Texas. It’s the first comprehensive map showing the exact locations where drilling is causing an increase in earthquakes.
The state hardest hit has been Oklahoma.
In 2011, the state suffered a 5.6 magnitude earthquake, the largest tremblor in the state since 1952. Although no one was seriously injured, the quake damaged a large number of buildings according to CNN.
Yahoo News also reports Oklahoma has beaten out California for the most 3.0 magnitude earthquakes.
Oklahoma has already taken steps to prevent future quakes. State regulators now require a seismic review for all disposal well sites. Likewise, the Oklahoma Corporation Commission, has ordered many disposal wells to stop drilling operations.
Nevertheless, predicting risk, and thereby regulating drilling practices, is still difficult.
The report states, “difficulties in assessing seismic hazard arise from a lack of relevant technical information on human industrial activity (that is, pumping data for injection wells).”
Still, people have apparantly been able to stop earthquakes through policy decisions. According to the New York Times, in at least two areas, policy planners managed to stop the earthquakes almost entirely by ending wastewater injections: once north of Denver int he 1970s and again in central Arkansas in 2011.
Another factor that’s difficult to assess is the potential size of a man-made earthquake. Mark Petersen, lead author of the Geological Survey report explained dramatic earthquakes are unlike, but possible.
“I’m not necessarily saying that we’re going to have a 7 in Oklahoma. But I don’t think we can rule that out.”
Scientists blamed a 7.9 magnitude earthquake in Sichuan, China on human activity, although it wasn’t from drilling, but water built up behind a dam.
[Image Credit: Getty Images]