The revolution in horizontal fracking–the “shale revolution” as it’s been described–arrived with an unexpected corollary: tremors in the ground. Residents have long suspected that the extraction techniques and the injection of wastewater have destabilized the ground beneath them, leading to these tremors. But new research out of the University of Texas and Southern Methodist University says these quakes have been happening a lot longer than fracking has been common practice.
Cliff Frohlich, senior research scientist and associate director for the Institute for Geophysics at UT Austin, is the paper’s lead author.
“We find earthquakes as early as 1925 on the Houston ship channel were almost certainly manmade in origin,” Frohlich says.
While the biggest earthquakes in Texas are natural, the study concludes that since 1975, 59 percent of the earthquakes were likely caused by humans.
The rate of earthquakes is increasing in Texas and people are beginning to take notice. “Prior to 2008 there were about two per year…since then there has been about 12 per year,” Frohlich explains.
Listen to the full interview in the player above.