The US Geological Survey (USGS) has released a map of earthquakes believed to be the result of human activity. Experts say most of the quakes were caused by the oil and gas industry injecting wastewater underground. Fracking was also blamed in some cases.
All of the areas highlighted on the chart “are located near deep fluid injection wells or other industrial activities capable of inducing earthquakes,” the study said.
Such injection-induced earthquakes are occurring at a rate higher than before, according to the USGS.
Scientists said the increase in seismic activity throughout the country is mainly due to the oil and gas industry injecting wastewater deep underground, which can activate dormant faults.