Scientists Warn of Earthquake Risk From Fracking

The process of fracking has transformed the U.S. energy industry into the single largest producer of oil and gas in the world. However, the fracking process results in large amounts of wastewater that is injected into deep disposal wells thousands of feet into the ground. The EPA estimates that there are 144,000 such wells receiving more than 2 billion gallons of fluid per day. Is this safe? Of course not. The final conclusive research isn't totally completed yet, but a number of scientists are convinced that not only do leaks in the system cause ground water to go bad but now fracking is believed to be causing a massive amount of new and more deadly earthquakes. 

So far this year, Oklahoma has reported 109 earthquakes through April 6 -- topping the total for all of 2013, and many of those quakes, as well as ones in Texas and northeastern Ohio, are thought to be linked to fracking activity. Worse yet, scientists are not yet able to predict which wastewater injection sites are likely to pose risks to buildings or critical structures such as power plants, and do not yet know what operators might do to mitigate the hazard. And new research indicates that the disposal wells are capable of affecting earthquake faults that are miles away from them. The warning comes as evidence continues to accumulate that the activities associated with the North American oil and gas boom can lead to unintended, man-made tremors, or "induced seismicity," 

Scientists once believed that such induced quakes would be small enough to be little more than minor annoyances. But that thinking began to change after a 5.3 magnitude earthquake struck Colorado in August 2011, and a 5.7 magnitude earthquake rattled Oklahoma three months later. A paper published in the scientific journal Geology in 2013 found that the tip of the Oklahoma quake's initial rupture plane was less than 200 meters (656 feet) away from injection wells, and concluded that years of injecting fluid into them had altered the pressure on the fault. That paper's lead author, Cornell University geophysicist Katie Keranen, released a new paper at the conference, which found that four high-volume wastewater injection wells in Oklahoma had triggered a swarm of small earthquakes about 9.3 miles (15 kilometers) away. It's not necessary for wastewater in an underground reservoir to actually reach an earthquake fault directly, because "the pressure can travel," Keranen explained. 

It's difficult to predict where wastewater injection might increase the risk of earthquakes, because researchers' knowledge of where faults are located remains incomplete, USGS researcher Rubinstein said. That is a particular problem in regions with oil and gas exploration that are not traditionally thought of as earthquake zones, such as Oklahoma and Ohio, where scientists said fracking itself, and not wastewater injection, triggered a series of quakes last fall. USGS is just now beginning to gather and include data on induced seismic activity in its maps of seismic risk, he said. "We might have earthquakes happen in places where they normally would occur over long time scapes," Atkinson said. "The earthquake that's triggered would happen anyway, but maybe it wouldn't have happened for 1,000 or 10,000 years."