Friday, April 13, 2012

Waste Well Injection Connected To Midwest Earthquakes

Speaking of deep tunnels, several geologists from government and academia are discerning a pattern of Midwestern earthquakes associated with deep well injection of industrial waste water. The background rate of midcontinent U.S. earthquakes was about 20 per year. In 2008 there were 29, then 87 in 2010 and 134 in 2011. U. S. Geological Survey seismologist Bill Ellsworth noticed clusters of these quakes near industrial wastewater wells in Oklahoma and Colorado. The theory is that the injected waste water lubricates existing earth crust faults, accelerating earthquake occurrence.

“Small perturbations can tip the scales,” Ellsworth says, “allowing an earthquake that might not otherwise happen for a very long time.”  University of Memphis seismologist Steve Horton has tracked a swarm of similar quakes in 2010 and 2011 along an Arkansas fault line. “The earthquakes that happened then in a swarm followed the startup of two waste disposal wells that were within 5 kilometers of this fault.” Horton says. “The earthquakes started after the injection at the two wells started, and they stopped after the injection stopped.”

Columbia University seismologist John Armbruster has been monitoring a series of significant quakes near wastewater injection sites in Youngstown and Marietta, Ohio.  The biggest Youngstown quake was the day after injection of wastewater into the well there stopped. “The number of earthquakes there has dramatically reduced, which I would think you would take as evidence that the well was triggering the earthquake,” Armbruster remarks.

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