CMA Foundation is a 501(C)3 organization and a subsidiary of the California Medical Association. Â©
The study, published Tuesday in Seismological Research Letters, reports that fracking waste injection wells are now the leading cause of earthquakes in Texas. Hydraulic fracturing, or fracking, involves thrusting chemicals and water against shale rock to break it up and release oil or gas. The process produces large amounts of waste fluid, or brine, that is either recycled or disposed of in injection wells.
Concerns include the possibility of earthquakes triggered by the fracking process which injects water, sand and various chemicals under high pressure into the ground to break the rock to release oil and gas for extraction. (David Mcnew/Getty Images)