The controversial practice of hydraulic fracturing to extract natural gas does not pose a high risk for triggering earthquakes large enough to feel, but other types of energy-related drilling can make the ground noticeably shake, a major government science report concludes.The bottom line is, there's not a whole lot of shaking going on. That's not stopping some people from their anti-fracking crusade, but this will be good news for those who are willing to take a more reasonable approach.
Even those man-made tremors large enough to be an issue are very rare, says a special report by the National Research Council. In more than 90 years of monitoring, human activity has been shown to trigger only 154 quakes, most of them moderate or small, and only 60 of them in the United States. That's compared to a global average of about 14,450 earthquakes of magnitude 4.0 or greater every year, said the report, released Friday.
Most of those are caused by gas and oil drilling the conventional way, damming rivers, deep injections of wastewater and purposeful flooding.
Only two worldwide instances of shaking — a magnitude 2.8 tremor in Oklahoma and a 2.3 magnitude shaking in England— can be attributed to hydraulic fracturing, a specific method of extracting gas by injection of fluids sometimes called "fracking," the report said. Both were last year.
"There's a whole bunch of wells that have been drilled, let's say for wastewater and the number of events have been pretty small," said report chairman Murray Hitzman, a professor of economic geology at the Colorado School of Mines. "Is it a huge problem? The report says basically no. Is it something we should look at and think about? Yes."
Saturday, June 16, 2012
Much Ado About Fracking
When it comes to fracking, the hype and hysteria doesn't quite match reality: