"Earthquakes are a natural hazard — except when they're man-made. The oil and gas industry has aggressively adopted the technique known as hydraulic fracturing, or fracking, to shatter subsurface shale rock and liberate the oil and gas lurking there. But the process results in tremendous amounts of chemical-laden wastewater. Horizontal drilling for oil can also produce massive amount of natural, unwanted salt water. The industry disposes of this wastewater by pumping it into deep wells.
And the Earth moves."
|USGS map displaying 21 areas impacted by induced earthquakes as well as the location of the fluid injection wells that have and have not been associated with earthquakes. (Courtesy of USGS)|
The USGS announcement of the press conference during which this data was released http://www.usgs.gov/newsroom/article.asp?ID=4486&from=rss_home#.VvnG2vkrLIU
The Earthquake Hazards Program can be found here http://earthquake.usgs.gov/