Fracking Can Cause Earthquakes: Here Is How

Fracking can produce persistent earthquakes even after it has ended, a team of researchers from Canada found.

Over the past years, there have been occurrences of earthquakes in various locations not usually associated with seismic activity. It is believed that fracking could have contributed to these earthquakes but the exact mechanism is still poorly understood, not until now.

Researchers at the University of Calgary in Alberta who studied earthquakes near Fox Creek suggest that quakes were actually man-made in two ways -- by increasing pressure as the practice occurred and even after the procedure was completed because of the pressure chances by the remaining fracking fluid.

"Hydraulic fracturing has been inferred to trigger the majority of injection-induced earthquakes in western Canada, in contrast to the midwestern United States where massive saltwater disposal is the dominant triggering mechanism," the researchers said in the study published in the journal Science.

These are the two types of human-induced earthquakes -- hydraulic fracturing or "fracking" and massive saltwater disposal. Though these two may indeed cause seismic activity, the researchers led by Xuewei Bao and David W. Eaton focused on fracking, which is rampant in Canada.

Hydraulic fracturing entails the injection of water deep underground where the high pressure causes cracks to form, allowing oil and gas to drip into a wellbore. Fracking fluid, which contains salt, water, sand and other additives, cracks the underground rocks to release oil and gas.

Though some scientists studying earthquakes have asserted that fracking is not a cause of earthquakes, the researchers demonstrated that fracking caused tremors in western Canada because they have added pressure to tectonic faults. As a result, when the buildup of pressure is too high, it may lead to the slipping of tectonic plates.

"I think the activities in that area are highly regulated to reduce the impact on wildlife, but nevertheless there are always concerns," said Eaton, as reported by PBS.

"I think that the government regulators in western Canada are very diligent in trying to reduce the impact of these activities," he added.

The researchers plan to conduct more research on the link between fracking and seismic activities. They also want to study the reason why earthquakes in various locations behave differently like those in Oklahoma.