The Truth Behind Hydrualic Fracturing

Fracking has been associated with concerns over potentially induced earthquakes. These concerns have surfaced due to the process in which fracking is used. In order to extract hydrocarbons (natural gas) from shale formations, networks of open fractures must be established through the use of pressurized injection of water into the formation; thus, fracking intentionally induces micro earthquakes of magnitude less than 1.0.* Although the main portions of the fracking procedure has not produced many significant earthquakes in the Marcellus Shale, there is seismic hazard when it comes to disposing wastewater into injection wells and basement formations.* This wastewater disposal may have contributed to the 5.7 magnitude earthquake that occurred in 2011 in central Oklahoma. The earthquake sequence initiated close to a pair of wastewater-injection wells where disposal operations began in 1993.* Prior to 2010, no unusual seismic activity was detected in this region. It appears that the 2011 central Arkansas  and the 2011 Youngstown, Ohio earthquakes (magnitudes 4.7 and 4.0, respectively) were both induced by wastewater-injection wells.* Again, although the actual fracking itself has only induced earthquakes that have all been below the damage threshold for modern building codes, the management of the wastewater in deep injection wells (which are the current method for disposal) can cause significant problems.