FACT SHEET: Exceedingly Low Risk of Earthquakes from Hydraulic Fracturing
Recently there have been a number of headlines linking the practice of hydraulic fracturing to seismic activity. In reality, experts from across the nation have noted that the risk and occurrence of these events is extremely low.
According to a recent peer-reviewed paper by researchers at Durham University that studied 198 instances of human-caused earthquakes since 1929, fracking is “not a significant mechanism” for inducing seismic activity. According to the authors, only one of these instances was indirectly related to hydraulic fracturing.
As lead author Richard Davies explains in the New Civil Engineer (sub req’d):
“It is worth bearing in mind that other industrial-scale processes can trigger earthquakes including mining, filling reservoirs with water and the production of oil and gas…we have concluded that hydraulic fracturing is not a significant mechanism for inducing felt earthquakes. It is extremely unlikely that any of us will ever be able to feel an earthquake caused by fracking.”
Indeed, induced earthquakes have been very low on the Richter scale. As the Seismological Society of America recently observed, “It remains rare for hydraulic fracturing to cause larger earthquakes that are felt by humans.” As Mark Zoback, Stanford University geophysicist and advisor to the Obama Administration, explains, this is largely because microseismic events that occur during fracking operations “affect a very small volume of rock and release, on average, about the same amount of energy as a gallon of milk falling off a kitchen counter.”
In fact, the seismic events you’ve heard about are more often tied to a separate process called wastewater injection – yet experts have observed that the risk associated with wastewater disposal is also quite low. According to the National Research Council:
“Injection for disposal of wastewater derived from energy technologies into the subsurface does pose some risk for induced seismicity, but very few events have been documented over the past several decades relative to the large number of disposal wells in operation.”
Bill Ellsworth of the U.S. Geological Survey also pointed out that this risk associated with disposal wells is manageable:
“In many of these cases, it’s been fixed by either shutting down the offending well or reducing the volume that’s being produced. So there are really straight-forward fixes to the problem when earthquakes begin to occur.”
While the risk is already low, any incident leaves room for improvement and state regulators are working to make it even lower. In Ohio, for example, the Department of Natural Resources recently announced new rules on well stimulation activity in the state, including stronger permit conditions that “place significant restrictions on developing shale resources near known fault areas or areas with past seismic activity.”
Check out EID’s new fact sheet—Exceedingly Low Risk of Earthquakes from Hydraulic Fracturing—for more on this topic from scientists and experts in the field.