By Laura Beans
The increased rates of earthquakes occurring in the central and eastern U.S over the past few years is a growing cause of concern. Two recent reports delve into the probability of man-made, induced earthquakes.
According to the U.S Geological Survey (USGS), more than 300 earthquakes above a magnitude 3.0 occurred from 2010-2012, compared with a much lower national average rate of 21 earthquakes per year observed from 1967-2000. The USGS also found that the increase in seismic activity coincides with the injection of wastewater in deep disposal wells. Much of this is a byproduct of oil and gas production which uses the process of fracking for extraction. The fracking wastewater is disposed of into wells specifically designed and approved for this purpose.
Seismicity of the coterminous U.S. and surrounding regions, 2009–2012. Black dots denote earthquakes with a magnitude ≥ 3.0 are shown; larger dots denote events with a magnitude ≥ 4.0. Background colors indicate earthquake hazard levels from the U.S. National Seismic Hazard Map (NSHM). Graphic courtesy of U.S. Geological Survey
The journal Science published a report Thursday, concluding that powerful earthquakes thousands of miles away can trigger swarms of minor quakes near wastewater-injection well sites like those used in oil and gas recovery, sometimes followed months later by quakes big enough to destroy buildings.
For the rest of this story please click the link to EcoWatch: http://ecowatch.com/2013/earthquakes-linked-to-fracking-wastewater-injection-wells/