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In this Nov, 6, 2011 file photo, Chad Devereaux examines bricks that fell from three sides of his in-laws home in Sparks, Okla., following two earthquakes that hit the area in less than 24 hours.
Millions at risk from man-made earthquakes
7 million people in the central and eastern U.S. live where damaging man-made earthquakes are likely to occur, according to a first-of-its-kind report released Monday by federal scientists from the U.S. Geological Survey.
Oklahoma, Kansas, Texas, Colorado, New Mexico and Arkansas are the most at-risk states from man-made quakes, according to the report.
The chance of damage from earthquakes in some of these states equals that of natural earthquakes in high-hazard areas of California.
“By including human-induced events, our assessment of earthquake hazards has significantly increased in parts of the U.S.,” said Mark Petersen, head of the U.S.G.S. National Seismic Hazard Mapping Project.
Earthquakes can be triggered by human activities, with wastewater disposal from the fracking process being the primary cause for recent events in many areas, the U.S.G.S. report said.
Fracking, or hydraulic fracturing, has spurred a boom in oil and natural-gas production. The fracking process blasts millions of gallons of water — mixed with sand and chemicals — deep underground to break apart shale deposits and release natural gas.
The central U.S. has seen the most dramatic increase in seismic activity over the past six years. From 1973 to 2008, there were about 24 earthquakes of magnitude 3.0 and larger per year.
But from 2009 to 2015, the rate steadily increased, averaging 318 per year and peaking in 2015, with 1,010 earthquakes.
The report notes that only a small percentage of fracking sites have been related to earthquakes, as an energy spokesperson notes:
“The vast majority of injection wells are not associated with earthquakes, a fact that’s confirmed by the U.S. Geological Survey’s report," according to Katie Brown, a spokesperson for Energy In Depth, a program of the Independent Petroleum Association of America.
"Data from the USGS and peer-reviewed studies show that less than one percent of injection wells across the United States have been even potentially linked to small earthquakes," Brown added. "This is a complex issue, and most earthquakes are not induced. But this is also an issue that scientists say — with near uniformity — can be effectively managed.”