A new report by the National Research Council is saying that hydraulic fracturing does not pose a high risk for causing earthquakes large enough to feel.
According to The Seattle Times, other energy-related drilling can trigger noticeable tremors, but overall, human-caused quakes are only at 154, compared to the global average of about 14,450 a year.
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."