7 million Americans at risk of fracking-related earthquakes, USGS says

By Joel Achenbach March 28 at 12:07 PM

 

U.S. Geological Survey map shows the potential for Americans to experience damage from natural or human-induced earthquakes in 2016. Changes range from less than 1 percent to 12 percent. (Courtesy of USGS)

Earthquakes are a natural hazard -- except when they're man-made. The oil and gas industry has aggressively adopted the technique known as hydraulic fracturing, or fracking, to shatter subsurface shale rock and liberate the oil and gas lurking there. But the process results in tremendous amounts of chemical-laden wastewater, which the industry disposes of by pumping into deep wells.
And the Earth moves.
On Monday, the U.S. Geological Survey published for the first time an earthquake hazard map covering both natural and "induced" quakes. The map and an accompanying report indicate that parts of the central United States now face a ground-shaking hazard equal to the famously unstable terrain of California.
Some 7 million people live in places vulnerable to these induced tremors, the USGS concluded. The list of places at highest risk of man-made earthquakes includes Oklahoma, Kansas, Texas, Arkansas, Colorado, New Mexico, Ohio and Alabama. There are also states with wastewater-disposal wells but no record of recent natural earthquakes -- suggesting that the practice of injecting wastewater deep into the Earth can be done more safely in some places than in others.

USGS map displaying 21 areas impacted by induced earthquakes as well as the location of the fluid injection wells that have and have not been associated with earthquakes. (Courtesy of USGS)

 

 It's not immediately clear whether this new research will change industry practices, or even whether it will surprise anyone in the areas of newly estimated risk. In Oklahoma, for example, the natural rate of earthquakes is only one or two a year, but there have been hundreds since fracking became commonplace in the last decade. "By including human-induced events, our assessment of earthquake hazards has significantly increased in parts of the U.S.,” Mark Peterson, chief of the USGS National Seismic Hazard Mapping Project, said in a release.
The report, based on recent seismic activity, is just a one-year hazard assessment. In effect, the scientists have said that what has happened in the recent past with induced earthquakes will likely happen in the near future -- hardly a radical finding. The goal is to help communicate the risks to the general public. Past USGS hazard maps didn't include man-made events.

USGS map displaying 21 areas where scientists have observed rapid changes in seismicity that have been associated with wastewater injection. The map also shows earthquakes - both natural and induced - recorded from 1980 to 2015 in the central and eastern U.S. with a magnitude greater than or equal to 2.5. (Courtesy of USGS)

“Having it quantified authoritatively will be helpful in establishing just how much danger there is," Michael Blanpied, associate coordinator of the USGS Earthquake Hazards Program, told The Post.
With a few exceptions, locations in the nation's central and eastern regions are not generally thought of as seismically unstable. But, Blanpied said, “Pretty much everywhere has faults. The nation was built over a billion years, and lots and lots of faults are left over from the construction process.”

Полная версия: https://www.washingtonpost.com/news/speaking-of-science/wp/2016/03/28/new-seismic-hazard-map-includes-fracking-related-quakes-for-the-first-time/?wpisrc=al_alert-hse