A spate of earthquakes across the middle of the U.S. is “almost certainly” man-made, and may be caused by wastewater from oil or gas drilling injected into the ground, U.S. government scientists said in a study...“Our scientists cite a series of examples for which an uptick in seismic activity is observed in areas where the disposal of wastewater through deep-well injection increased significantly,” David Hayes...of the U.S. Department of Interior said...The earthquakes were “fairly small,” and rarely caused damage, Hayes said...Daniel Whitten...[of] America’s Natural Gas Alliance, which represents companies such as Chesapeake Energy Corp. (CHK) and Cabot Oil & Gas Corp. (COG), said...“There are over 140,000 disposal wells in America, with only a handful potentially linked to seismic activity....We are committed to monitoring the issue and working with authorities...but...there is no scientific data associating hydraulic fracturing with earthquakes that would cause damage”...