The surge in earthquakes shaking Oklahoma, Texas and other parts of the nation’s mid-section are likely caused by million of gallons of toxic oil and gas wastewater being disposed of underground, two new studies have found.
Scientists at the University of Colorado Boulder and the United States Geological Survey analyzed data from earthquakes and more than 106,000 active injection wells across the central and eastern part of the nation, the largest such study to date. They found that “the entire increase in the number of earthquakes in the U.S. midcontinent is associated with injection wells,” according to Matthew Weingarten, a doctoral candidate at the university who led the study.
Weingarten and his colleagues also discovered that wells blasting the most wastewater into the ground, and at a faster rate–more than 300,000 barrels a month–were more likely to be linked to earthquakes. Their research was published Thursday in the journal Science.
Similarly, two geologists at Stanford University discovered that greater seismicity in certain counties in Oklahoma was often preceded by 5- to 10-fold increases in the volume of wastewater injected. Their findings were published Thursday in the journal Science Advances.