Oklahoma had more than 250 times the normal number of earthquakes last year. That's the largest rise of any state over the past six years, according to the U.S. Geological Survey, and state officials say the temblors are "very likely" linked to the injection of oil and gas drilling wastewater into disposal wells. Colorado hasn't seen as many so-called "induced" earthquakes, but there have been incidents here dating back to the 1960s. Joe Wertz, of StateImpact Oklahoma, spoke with Ryan Warner about new research into connections with oil and gas operations. Click on the audio link to hear the conversation.
