And since fracking produces large quantities of wastewater, drilling companies use deep wells to dispose the waste. Scientists believe that these wells are the main culprit to the rise of earthquakes in the U.S. One particular example shows that the 2011 magnitude 5.7 quake in Oklahoma was likely caused by fluid injection.
Scientists from the University of Oklahoma, Columbia University, and U.S. Geological Survey, used the quake’s aftershocks to map fault patterns and to reveal how the pressure built over time as water from fracking was disposed roughly 250 meters away from the epicenter. “The future probably holds a lot more in induced earthquakes as the gas boom expands,” says Art McGarr, a USGS Earthquake Science Center researcher.