More than a dozen areas in the US have been shaken by small earthquakes triggered by oil and gas drilling , according to a government report released today . The man-made quakes jolted once stable regions in eight states , including parts of Alabama , Arkansas , Colorado , Kansas , New Mexico , Ohio , Oklahoma and Texas . Earthquakes , they said , were sometimes caused by fracking , in which large volumes of water , sand and chemicals are pumped into rock formations to free oil or gas . Scroll down for video . The study identified 17 areas in the central and eastern US with increased rates of induced seismicity . Since 2000 , several of these areas have experienced high levels of seismicity . Researchers say there have been 'substantial increases since 2009 that continue today ' They said the spike in seismic activity was largely down to the oil and gas industry injecting wastewater deep underground , which can activate dormant faults . Many studies have linked the rise in small quakes to the injection of wastewater into disposal wells , but the Geological Survey 's report takes the first comprehensive look at where the man-made quakes are occurring . 'The hazard is high in these areas , ' said Mark Petersen , who leads the agency 's national mapping project . Oklahoma lately has been rocked by more magnitude-3 quakes than California , the most seismically active of the Lower 48 states , Petersen said . Oklahoma was not on scientists ' radar until recently when the state experienced a spate of quakes , the largest registering a magnitude-5.6 in 2011 . A 2014 United States National Seismic Hazard Maps with the areas most at risk shown in warmer colours . Recently , man-made quakes jolted once stable regions in eight states , including parts of Alabama , Arkansas , Colorado , Kansas , New Mexico , Ohio , Oklahoma and Texas . The cumulative number of earthquakes with a magnitude of 3.0 or larger in the central and eastern US , 1973-2014 . The rate of earthquakes began to increase starting around 2009 and accelerated in 2013-2014 . Earlier this week , the Oklahoma Geological Survey acknowledged that it is very likely most of the recent shaking is from wastewater disposal . Many faults awakened by drilling have not moved in millions of years , Geological Survey geophysicist William Ellsworth said . 'They 're ancient faults , ' Ellsworth said . 'We do n't always know where they are . ' A message to the American Petroleum Institute was not immediately returned . The industry group has said efforts are made to map fault lines where drilling occurs . The fluid pressure in the pores and fractures of the rocks is called the 'pore pressure . ' The pore pressure acts against the weight of the rock and the forces holding the rock together . If the pore pressures are low - especially compared to the forces holding the rock together - then only the imbalance of natural in situ earth stresses will cause an occasional earthquake . If , however , pore pressures increase , then it would take less of an imbalance of in situ stresses to cause an earthquake . This type of failure is called shear failure . Injecting fluids into the subsurface is one way of increasing the pore pressure and causing faults and fractures to 'fail ' more easily . Earthquakes can be caused by injecting fluid into the subsurface or by extracting fluids at a rate that causes subsidence and slippage along planes of weakness in the Earth . Source : US Department of Energy . Increases in the number of tremors from 1960-2010 shown in various regions of the US . Scientists said it 's difficult to know what jobs will trigger shaking . A group of experts met last year in Oklahoma to pinpoint seismic hotspots around the country caused by induced quakes . Scientists initially identified 14 regions affected by quakes linked to drilling . They later added three other high-risk areas - northern Oklahoma-southern Kansas ; Greeley , Colorado ; and Azle , Texas . The findings were released at a Seismological Society of America meeting in Pasadena , California . Seismic hazard maps produced by the Geological Survey and used for building codes and insurance purposes do n't include quakes caused by the oil and gas industry . Scientists said it 's difficult to know what jobs will trigger shaking . Researchers study man-made quakes in the affected areas to determine how often they are expected to occur in the next year and how much shaking they would produce . A series of earthquakes that rattled a small Texan community have been linked to nearby oil and gas operations . In this image red squares are injector locations ; pink arrows , approximate location of two large brine production wells that are located both near the faults and near reported earthquakes swarms .
Man-made quakes have hit once stable regions in central and eastern US . Score: 7