Fracking operations in Oklahoma have been blamed for the recent surge in earthquake activity in the state.

A new research paper published in Science says the injection of wastewater from hydraulic fracturing is “likely responsible” for a forty-fold jump in seismic activity over a five-year period.

The study focused on four wells the oil and gas industry has used to dispose of chemical-laden water left over from the fracking process. The researchers said that disposal could be responsible for earthquakes occurring up to 35 kilometers (22 miles) from the well sites.

The small town of Jones has experienced more than 2,500 earthquakes magnitude 3.0 and greater since 2008 that researchers say were triggered by a significant increase in wastewater injection volumes. The four well sites have disposed of approximately four million barrels of water a month deep below the earth’s surface.

Geologists say the injection of so much water could increase subterranean pressure near underground faults, helping push them past their tipping point. “It is possible that pressure looks to have risen in the places where the earthquakes are occurring,” Katie Keranen of Cornell University and the study’s lead author told BBC News.

“That pressure increase is what we see in natural triggering. So, if a fault is close to failure, the amount that the pressure is going up at these locations in our model is enough to push them over the edge,” she added.

-Noel Brinkerhoff

To Learn More:

Sharp Increase in Central Oklahoma Seismicity 2009-2014 Induced by Massive Wastewater Injection (by K.M. Keranen, M. Weingarten, G.A. Abers, B.A. Bekins, S. Ge, Science)

Wastewater from Energy Extraction ‘Triggers US Quake Surge’ (by Matt McGrath, BBC News)

U.S. Geological Survey Calls Oklahoma Quake the Largest “Human-Induced” Earthquake on Record (by Steve Straehley, AllGov)