A 2011 earthquake that registered a 5.6 on the richter scale and destroyed 14 homes, is now believed to have been man-made. Scientists announced Wednesday that the quake, originally believed to have naturally occurred, was most likely the result of deep injections of waste water, a byproduct of oil drilling. If they are right, it would make the Oklahoma quake the largest man-made seismological event in recorded U.S. history.
The study was carried out by a group of researchers from the University of Oklahoma, Columbia University, and the U.S. Geological Society. They believe that waste water pumped into empty oil wells put increasing pressure on the fault line running underneath the area, causing small tremors and eventually, the quake. 'When you overpressure the fault, you reduce the stress that's pinning the fault into place and that's when earthquakes happen,' said study co-author and Columbia geophysicist Heather Savage.
The study raises even more concerns over the practice of fracking, which pushes large volumes of water underground in order to release natural gas reserves.