The United States Geological Survey (USGS) has finally confirmed that wastewater fracking is causing earthquakes, in a newly released report.
According to the report, the state of Oklahoma has experienced the highest number of earthquakes thought to be caused by man-made activity in the central and eastern United States.
One such incident was a 5.6-magnitude earthquake in 2011. The initial shaking was caused by a foreshock originating in an area only 200 yards away from a spot where wastewater fracking had been taking place for 18 years. The water caused pressure changes underground, leading to an earthquake felt in at least 17 states.
"These earthquakes are occurring at a higher rate than ever before, and pose a much greater risk and threat to people living nearby," said USGS National Seismic Hazard Modeling Project chief Mark Petersen.
Hydraulic fracking is the process of shooting high-pressure streams of water, chemicals and sand deep into the ground to extract natural gas and oil. When the byproduct wastewater is injected thousands of feet into the ground, in the process known as wastewater fracking, the water can result in earthquakes — by disturbing faults that have not moved for long periods of time.
However, the report also notes that in some areas, the disposal of toxic wastewater does not lead to similar man-made earthquakes. Experts hope that by studying areas where wastewater fracking has no impact, a way can be found to continue fracking activities without the risk of causing earthquakes.
The study maps 50 years of information for 17 zones believed to be sites of man-made earthquakes, spanning eight states. The areas are said to all be in locations near wastewater fracking sites or other industrial activities considered capable of causing earthquakes.
The proposal that injecting water into deep parts of the ground could lead to earthquakes has been under debate for decades, dating back to the 1960s when over 1,000 small earthquakes in Colorado were attributed to chemical waste fluid deposited inside a well 12,000 feet underground.
Researchers believe that additional studies could help authorities to better control the risks of wastewater fracking and man-made earthquakes. There are also proposals for developing upgraded seismic sensors to better track earthquakes that are smaller in magnitude.
According to Caltech seismologist Egill Hauksson, wastewater fracking should stop once small earthquakes are felt. If there are no earthquakes, then it should be safe to continue. However, Hauksson added, getting to the point of making proper assessments will require additional research.
Don't forget to follow T-Lounge on Twitter and visit our Facebook page.
Photo: Casey Hugelfink | Flickr
