One more reason why I’m not too thrilled about the natural gas drilling in Pennsylvania’s Marcellus Shale. Our state sits on granite, and there happens to be a fairly large earthquake fault. Because of the granite, it has the potential for much more serious damage:
Saltwater pumped deep into the earth in a natural gas mining operation offers a “plausible,” though not definitive, explanation for small earthquakes in Texas in 2008 and 2009, scientists say.
On Oct. 31, 2008, small (magnitude 3.0) tremblors shook homes in the Dallas-Fort Worth area. Similar shakes (3.3) occurred again last May.
“The earthquakes were right in our backyard, and quakes don’t happen too often in Texas,” says seismologist Brian Stump of Southern Methodist University in Dallas, senior author on a Leading Edge journal study. “We usually only get small ones.”
Some suspicions centered on wells involved in “hydraulic fracturing” of shale layers in Texas and elsewhere. The shale is cracked by injections of high-pressure water, loaded with sand, to free natural gas trapped within. The U.S. Geological Survey estimates that 200 trillion cubic feet of natural gas may reside in shales nationwide.