Fracking-Linked Earthquakes May Strike Far from Wells

From an Article by Becky Oskin, Live Science, May 4, 2014

ANCHORAGE, Alaska — Fracking may cause earthquakes much farther from the sites of its wastewater wells than previously thought, researchers said here Friday (May 2) at the annual meeting of the Seismological Society of America.

In central Oklahoma, a cluster of four high-volume wastewater injection wells triggered quakes up to 30 miles (about 50 kilometers) away, said lead study author Katie Keranen, a geophysicist at Cornell University in New York. The earthquakes have since spread farther outward, as fluids migrate farther from the massive injection wells, she said.

“These are some of the biggest wells in the state,” Keranen said. “The pressure is high enough from the injected fluids to trigger earthquakes.”

Scientists here noted the vast majority of injection wells haven’t triggered any quakes, and the link between earthquakes and fracking or wastewater injection is not conclusive. However, there are now more earthquakes in the United States than before the fracking boom began.

Between 1967 through 2000, there were an average of 21 earthquakes yearly above magnitude 3.0. That rate shot up to an average of 300 earthquakes yearly after 2010. [See Photos of Earthquakes' Paths of Destructions]