Wastewater from Hydraulic Fracking Linked to EarthquakesJul 12, 2013
Disposing of wastewater from hydraulic fracturing—fracking—may make fault zones more prone to earthquakes, according to researchers from Columbia University and the University of Oklahoma.
In an article published Thursday in the journal Science, researchers found a “profound” increase in the number of earthquakes at three sites where fracking wastewater was injected into the ground, according to Nicholas van der Elst, from Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York. Fracking fluids are usually disposed of by injecting them into the ground. Van der Elst, the lead author, said the researchers found that, as subsurface rocks become saturated, fault lines in the disposal area may become less stable, Bloomberg News reports. “This study helps show the link between the pumping and the earthquakes,” van der Elst said.
The report found that significant seismic activity elsewhere on the planet may “induce” quakes in injection zones hours or days later. “Seismic waves from the distant earthquake can squeeze the rock like a sponge,” van der Elst explained. Researchers studying injection sites in Oklahoma, Texas, and Colorado recorded hundreds of earthquakes in a year when they might have expected a dozen, Bloomberg News reports.
According to the study, disposing of the wastewater and fluids by injecting them into the ground may have a greater impact on fault lines than fracking itself, which involves pumping liquids into the earth and then extracting them. According to Bloomberg News, the Science article notes that more than half of U.S. earthquakes of 4.5 magnitude or greater in the past decade “occurred in regions of potential injection-induced seismicity.”