Seven million people in central and eastern US are vulnerable to man-made earthquakes.
This is according to the first ever map of damaging quakes for this year, released today by the US Geological Survey.
The map shows how chance of damaging earthquakes hitting east of the Rockies has increased significantly, much of it a man-made byproduct of drilling for energy.
These earthquakes were sometimes caused by fracking, in which large volumes of water, sand and chemicals are pumped into rock formations to free oil or gas.
Oklahoma now has a 1 in 8 chance of damaging quakes in 2016, surpassing California as the state with the highest probability.
Natural earthquake risk also increased around the New Madrid fault in Missouri, Tennessee, Kentucky, Arkansas and Illinois
As a result, earthquakes caused by human activity will now be included in the U.S. Geological Survey's seismic risk maps.
'By including human-induced events, our assessment of earthquake hazards has significantly increased in parts of the US,' said Mark Petersen, Chief of the USGS National Seismic Hazard Mapping Project.
http://www.dailymail.co.uk/sciencetech/article-3512784/USGS-revises-seismic-risk-map-include-quakes-caused-humans.html