US government geologists have reported that the number of earthquakes in the central United States rose "spectacularly" near where oil and gas drillers fracked.
The average number of earthquakes of magnitude 3 or greater in the US mid-continent - an area that includes Arkansas, Colorado, Oklahoma, New Mexico and Texas - increased to six times the 20th century average last year, scientists at the US Geological Survey said in an abstract of their research.
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