MOSCOW, September 17 (RIA Novosti) - US Geological Survey (USGS) scientists have discovered that deep fluid injections in Colorado and New Mexico are behind the increasing number and strength of earthquakes the states are experiencing.
"Many lines of evidence indicate that this earthquake sequence was induced by wastewater injection," a team of four USGS researchers wrote in a report published in the Bulletin of the Seismological Society of America.
Natural gas producers routinely dispose of large volumes of wastewater by injecting it underground after drilling. Wastewater injections are also used to break up underground shale rock formations to make gas extraction easier, the Climate Progress website says.
This process is also known as "fracking" and is all the rage in the United States where shale gas makes up the largest share of exported natural gas and crude.
But studies suggest that injected wastewater moves along fault lines and causes them to fail, according to Climate Progress.
USGS experts studied a vast area around the Raton Basin that stretches from Colorado into New Mexico, and found that the basin started experiencing quakes shortly after drilling companies started injecting water mixed with abrasive sand and chemicals into the ground.
Despite having been seismically silent before 1999, the area registered a total of 16 earthquakes that can be described as large, including two quakes at 5.0-magnitudes. There had only been one 4.0-magnitude earthquake in the basin in the past 30 years.
The study noted however that the link between underground fluid injections and earthquakes is about as traceable as that between local natural disasters and the climate change. "For future research, a longer-term study with dense network coverage on both sides of the border would be especially useful in understanding the inducing relationship between the earthquakes and fluid injection in the Raton Basin," they concluded.
