Scientists say that a recent surge of low-magnitude earthquakes in Oklahoma is likely the result of the underground disposal of vast quantities of wastewater generated by oil and gas extraction. Temblors in Oklahoma used to be rare. Before 2008, the state experienced just one earthquake of magnitude 3 or larger each year. So far this year the state has already witnessed 230 quakes of that size-more than the number recorded in California. “There are large regions in the state that are lighting up” with quakes, said Katie Keranen, seismologist at Cornell University and lead author of a study on the Oklahoma temblors, published Thursday in the journal Science. “It’s a very profound increase.” The findings add to a growing body of evidence that various types of large-scale human activity–from coal mining and quarrying to building dams–can help to trigger quakes. In most cases, the geological processes […]