Man-Made Earthquakes Rising in US, New Maps Show
That's the conclusion in a first-ever report made public Monday from the U.S. Geological Survey, which cites the oil and gas drilling process as triggering the quakes. The assessment of human-induced seismic shaking found 7 million people in the central and eastern U.S. live in the man-made earthquake zone, said Mark Petersen, head of the USGS National Seismic Hazard Mapping Project.
Human activities, such as wastewater disposal from drilling for oil and gas can cause earthquakes the report said.
The central U.S. has seen the most dramatic increase in seismic activity over the past six years, the report found, as wastewater injection became more widespread. From 1973 to 2008, the USGS recorded more than 20 earthquakes of magnitude-3.0 and larger per year. Such events increased tenfold from 2009 to 2015 – to an average of 318 a year. In 2015, the USGS recorded 1,010 earthquakes.
The maps highlight 17 hotspots where communities face a significantly increased risk of earthquakes, and the accompanying report links the earthquakes to wastewater injection wells. Previous maps did not include earthquakes that are induced by human activities.Fracking fallout: 7.9 million at risk of man-made earthquakes - Mar. 29, 2016
"We consider induced seismicity to be primarily triggered by the disposal of wastewater into deep wells," said Mark Petersen, chief of the National Seismic Hazard Project for the U.S. Geological Survey, which released the maps on April 23. [Image Gallery: This Millennium's Destructive Earthquakes]
The earthquake hotspots include the states of Oklahoma, Kansas, Texas, Ohio, Arkansas, Alabama, Colorado and New Mexico. Until recently, many of these states were some of the places in the United States least likely to have an earthquake. But then, high oil prices brought in companies eager to exploit ancient seabeds where oil and gas mingle with brine.
People in parts of Texas and Oklahoma now face the same earthquake risk as those in California.Government scientists believe these quakes are mostly triggered by human activity, primarily the disposal of waste water as part of oil and natural gas drilling.
About 7.9 million people are now at risk from these man-made earthquakes, including certain regions in Oklahoma, Kansas, Colorado, New Mexico, Texas and Arkansas, the U.S. Geological Survey said this week. Even though these earthquakes don't factor in building-code maps, they create a hazard to buildings, bridges, pipelines and other key structures, according to the government agency that studies the U.S. landscape.
This is the first time the government has created maps that show the risk of so-called "induced" earthquakes. The agency defined these as tremors in a region with increased earthquake rates attributable to "human activities, such as fluid injection or extraction."