Map: 7 Million Americans At Risk From Quakes Caused By Human Activity

Due to the increased risk of earthquakes from human activity, the United States Geological Survey has, for the first time, mapped the threat they pose to humans across the United States.On Monday, the USGS published a map that charted which parts of the country are at the highest-risk of "human-induced" earthquakes for the year. Up to seven million people in the Central and Eastern United States are at risk from these earthquakes, according to the agency.

California and the West always remain at risk for seismic activity—thanks, San Andreas Fault—so scientists did not calculate the risk of human-induced quakes into their data. The most surprising part of the map is the big, red blob that covers a good portion of the Sooner State.

(USGS)
"My first thought was actually holy crap, Oklahoma is redder than California," wrote USGS geologist Susan Hough to the Washington Post in an email.

Indeed, Oklahoma has seen a swarm of earthquakes over the last few years, which researchers believe is related to wastewater disposal from oil and gas drilling. While the popular perception is to attribute these earthquakes to the controversial process come to be known as fracking, the USGS says "studies suggest that this process is only rarely the cause of felt earthquakes." The other states at elevated risk of human-induced quakes are, in descending order from highest to lowest, Kansas, Texas, Colorado, New Mexico and Arkansas.

In looking at the data, the USGS also identified 21 regions east of the Rocky Mountains that are at the highest risk of human-induced earthquakes. The most striking of these is a huge region that crosses Oklahoma and includes chunks of Kansas and Texas:

USGS
The risk, especially in Oklahoma, is very real. As Slate points out, from 1882 to 2012, there were only 232 earthquakes in the state that registered M3.0 or higher. In this year, alone, there have already been 287.