The number of people threatened by earthquakes as a result of fracking is expected to be half what it was last year, the U.S. Geological Survey said Wednesday.
Even with the projected risk dropping from 7 million people in 2016 to 3.5 million in 2017, the situation is more complicated than it appears, officials said on a call with reporters.
“The good news is that the overall seismic hazard for this year is lower than in the 2016 forecast, but despite this decrease, there is still a significant likelihood for damaging ground shaking in the U.S. in the year ahead,” said Mark Petersen, the head of the geological survey’s seismic mapping project.
The rate of earthquakes has declined in the central and eastern regions of the nation, he said. “That’s the good news,” he added. “But it’s a more complicated story because we’ve had more magnitude 5 earthquakes in Oklahoma than ever before.”
The federal agency began tracking manmade earthquakes last year, especially in Oklahoma where the frequency of quakes has been highest for a state not on a major geological fault. The increase in manmade earthquakes is tied to the practice of injecting wastewater from fracking deep underground for disposal.
Oklahoma has approved policies to reduce the rate of wastewater injection from fracking, which has led to a drop in the number of earthquakes. Also, a global oil glut forced drillers to curtail oil and natural gas operations in the last year.
Nevertheless, most of the risks still persist, with Oklahoma and southern Kansas leading the nation for manmade earthquakes this year, according to the agency.
