Overall numbers of suspected man-made earthquakes falling as key states try to control the shaking, but strong events plague parts of Oklahoma and Kansas.
A new earthquake hazard map for the central and eastern United States shows about 3.5 million people, primarily in Oklahoma and southern Kansas, are at high risk of experiencing a damaging man-made earthquake from oil and gas-related activities this year.
Researchers at the United States Geological Survey have produced a one-year seismic outlook that takes into account both natural and human-caused earthquakes, mainly those generated by the underground disposal of oil and gas wastewater and, to a lesser extent, by fracking itself.
In recent years, there has been a surge in quakes linked to oil and gas activity, including a massive 5.8 event last September in Pawnee, Okla. Some have caused damage to homes, buildings and roads across Oklahoma and elsewhere, sparking public concern and prompting regulators to begin restricting local energy company activities.
Despite some pockets of the country remaining on high alert for damaging shaking, the scientists did find the region's overall risk went down compared to last year, which was the first year of the seismic report. The 2016 forecast had indicated up to 7 million people had a chance of facing damage from a moderate man-made earthquake. The 2017 forecast was lower because the total number of earthquakes were lower in the study area in 2016 compared with 2015.
The scientists said the drop in earthquakes last year suggests man-made earthquakes can be controlled by reducing the fracking and/or wastewater disposal activity.
Read more at Millions Now at Risk from Oil and Gas-Related Earthquakes, Scientists Say