Scientists have linked the magnitude-5.3 quake with nearby wastewater injection, a process used in drilling. Associated Press A magnitude-5.3 earthquake that hit Colorado in 2011 was likely caused by the injection of wastewater into the ground, a process used in natural-gas drilling, according to new research to be released Tuesday. The new study, published in the Bulletin of the Seismological Society of America, adds more detail to a growing body of work seeking to establish and explain the connection between human activity and seismic events, known as induced quakes. Geologists have been intensely focused on the field in the past few years, as some states, including Oklahoma, Ohio, Colorado and New Mexico, have seen a rise in quakes that coincides with an uptick in activities associated with oil and gas extraction, scientists say. According to the American Petroleum Institute, […]