Monday, November 14, 2011
Earthquakes becoming more common in fracking-frenzied South Texas
Record setting earthquake about 50 miles SE of San Antonio
From Austin's KUTnews.org
A University of Texas seismologist says hyraulic fracturing itself does not cause earthquakes. But he says earthquakes have been associated with the disposal of fracking fluids.
“They [drilling companies] pump the water back into the ground into a deep aquifer to get rid of it,” earthquake researcher Cliff Frohlich at UT's institute for Geophysics told KUT News.
“The quakes have been associated with the pumping of water back into the ground, not the producing of the gas,” he said, pointing to seismic activity in North Texas and in Arkansas.
In September, Arkansas banned the use of deep wells to store waste water. StateImpact Pennsylvania points to a study by Southern Methodist University and UT that linked small earthquakes in the North Texas Barnett Shale with the practice, and says the Army Corps of Engineers has expressed concern about drilling for natural gas near dams.
But Frohlich says it’s too soon to say if waste water disposal activities were related to today’s 4.6 magnitude quake in South Texas. “That’s a question,” he said.
The area southeast of San Antonio has felt earthquakes before. There was a 4.3 magnitude earthquake in 1993 near the same location, and there have been smaller quakes recorded back to the 1970s, Frohlich said.