The report found that oil and gas drilling activity, particularly practices like hydraulic fracturing or fracking, is at issue. Saturday's earthquake spurred state regulators in Oklahoma to order 35 disposal wells, which are used by frackers, to shut down over a 500-square mile area. The Environmental Protection Agency is also assessing the region, Oklahoma Governor Mary Fallin said. Fracking is used by oil and gas producers to extract oil from the ground -- and it's behind the massive boom in U.S. oil production. The United States had 300,000 fracking wells last year, up from just 23,000 in 2000, according to the U.S. Energy Information Administration.

Source: CNN September 03, 2016 20:26 UTC