"In the five years since earthquakes first began blitzing Oklahoma, state officials have been hesitant to agree with scientists who blamed the oil and gas industry. The shaking doesn't appear to be slowing, but the regulatory response is ramping up as more state officials acknowledge the link between increased seismic activity and waste fluid pumped into the disposal wells of oil fields.

To show how an oil and gas boom fueled a massive surge of earthquakes, scientists used algorithms, statistics and computer models of fluid flow and seismic energy."

Joe Wertz report for NPR's All Things Considered September 16, 2015. [2]