The connection between natural gas fracking and earthquakes has just become a lot clearer.
Yes, there is an impact from drilling thousands of holes deep in the ground and dumping wastewater in them!
Oklahoma is not a place where people expect earthquakes, but it had a 5.7-magnitude quake in 2011 (the largest ever there), which scientists have now linked to fracking. It was caused by injecting wastewater deep into the ground.
According to the US Geological Survey, the central US experienced 21 earthquakes a year from 1970-2000, but there were 50 in 2009, 87 in 2010 and 134 in 2011.
Last year, those researchers said the earthquakes are "almost certainly" man-made, and likely connected to wastewater disposal.
Now, after a year-long study of the Oklahoma earthquake, researchers have published their findings in the journal, Geology. The study was jointly conducted by the University of Oklahoma, Columbia University and the U.S. Geological Survey.
"The findings are a cautionary note for disposal of the
millions of gallons of fluids from hydraulic fracturing," Katie Keranen, assistant professor at Oklahoma, told Bloomberg.
Because of this problem and other criticisms of the enormous amounts of water the industry consumes, the natural gas industry is increasingly turning to recycling water instead of dumping it, along with other greener technologies.
To get at the oil that lies in deep shale formations, water, sand and chemicals are injected underground – that literally splits the rocks, which frees trapped gas.
In Oklahoma, a series of small earthquakes triggered the larger tremor, but the "cascading series of tremors" shows "the risk of humans inducing large earthquakes from even small injection activities is probably higher" than thought, says Geoffrey Abers from the Lamont-Doherty Earth Observatory
at Columbia.
Commenting on the research, geophysicist Rowena Lohman
says "the likelihood of generating damaging earthquakes may be linked to the amount of pressure used in fluid injection, which is something that we can potentially oversee and control."
There are currently 150,000 water disposal injection wells operating in the US.
Cincinnati banned fracking after a disposal well in Youngstown was determined to be the cause of at least 11 earthquakes. A 4.0 magnitude earthquake followed 10 smaller tremors during 2011, all centered around the wells.
The wells were used to dispose millions of gallons of brine and other waste liquids created during the fracking process – injected under pressure into 9,200 feet deep wells.
We are still waiting for national regulations that protect the country from the many negative effects of this exploding industry. The Department of Interior proposed draft regulations for public lands last year, but they have yet to be finalized, and most drilling occurs on private lands.
The EPA issued air pollution standards for the industry, which govern a range of toxic emissions, but exclude the greenhouse gas, methane.
Because of these gaps, some in the natural gas industry joined with environmental groups and agreed on standards for the Northeast US just last week.
Read "Fracking’s Latest Scandal? Earthquake Swarms" at Mother Jones:
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