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BOB HIRSHON (host):
Manmade earthquakes. I’m Bob Hirshon and this is Science Update.
Wastewater from oil and gas extraction, including hydraulic fracking – is causing earthquakes in many parts of the United States that don’t normally see tremors. USGS seismologist Art McGarr says this non-potable water is often injected into porous limestone or sandstone deposits deep below the water table. This can trigger earthquakes when the water reaches seismic fault lines.
ART McGARR (USGS):
This year, Oklahoma has been as active as California, which is fairly amazing considering that before 2009, it was a state with almost no earthquake problem.
HIRSHON:
In a new study, McGarr and his colleagues traced a major uptick in quake activity in the Raton region of Colorado and New Mexico to wastewater disposal from methane extraction there.
McGARR:
The injection began in the late 1990s; the first sequence of earthquakes in August of 2001.
HIRSHON:
I’m Bob Hirshon, for AAAS, the science society.