Hydraulic fracturing may trigger seismic activity

A group of experts who have conducted research revealed that a series of earthquakes felt by the U.S. can be traced to human rather than natural geologic activity.  Experts say that drilling activities by firms which invest in oil and oil exploration activities like hydraulic fracturing, are “almost certainly” the culprits.

According to a group of U.S. Geological Survey researchers, an average of 21 earthquakes per year rocked the mid-portions of the U.S. from the years 1970 to 2000. However, this number had since risen to a yearly average of 50 and 87 in 2009 and 2010 respectively, and by 2011 it jumped to a staggering 134 yearly average.

These figures appear in a study to be taken up in a meeting to be held by the Seismological Society of America in San Diego, California.  Some observers say that the issue may once again put the energy sector in the hot seat.  At present, the industry is already beset with rules that curb its hydraulic fracturing activities and may eventually discourage oil investment and exploration endeavors.  Fracturing or fracking, in oil exploration, is done by injecting sand and chemicals with water into shale formations found deep under the earth’s surface.   The process fractures the rock formation and allows natural gas to leak out.  Water used for fracturing is waste water and is disposed of through injection into deep wells, treatment in water treatment facilities, or recycling.

Deputy Secretary David Hayes of the U.S. Department of Interior was referring to the U.S. Geological Survey research when he wrote that “Our scientists cite a series of examples for which an uptick in seismic activity is observed in areas where the disposal of wastewater through deep-well injection increased significantly”.

However, he commented that earthquakes in the area cannot be totally traced to waste-water disposal activities.  Moreover, the tremors were mild and damage (if any) was quite minimal. But authorities from Ohio have a different opinion. They believe that 2011 earthquakes that occurred in the area were possibly caused by waste-water from hydraulic fracking.

Daniel Whitten, a representative of America’s Natural Gas Alliance (ANGA) mentioned via e-mail that “There are over 140,000 disposal wells in America, with only a handful potentially linked to seismic activity”.

He added that there is no proven link between hydraulic fracking and destructive seismic activities. The seeming lack of evidence allayed investor fears about their investments in drilling and fracking activities.

However, more rules on emission and wastewater disposal are being readied by the Environmental Protection Agency.

The U.S. Interior Department may come up with laws targeted at revising well structures and may also require transparency on chemicals used for fracking within government property.

By Chris Termeer