The man-made earthquakes that have been shaking up the southern United States only stand to get stronger and more dangerous as the controversial practice of hydraulic fracturing, or fracking, increases, scientists warned at a Thursday conference.
According to multiple reports, scientists attending the Seismological Society of America annual meeting agreed that fracking can change the state of stress on existing faults to the point of failure, causing earthquakes. That stress is generally not caused by fuel extraction itself, but by a process called “wastewater injection,” where companies take the leftover water used to frack wells and inject it deep into the ground.
Though it was previously believed that the man-made earthquakes could not exceed a 5.0 magnitude, many now say that larger quakes could become the norm as more and more water is stored underground.
“I think ultimately, as fluids propagate and cover a larger space, the likelihood that it could find a larger fault and generate larger seismic events goes up,” Western University earth sciences professor Gail Atkinson reportedly said at the meeting.
Related Article: Oklahoma Scientist to Test if Fracking Causes Earthquakes
Because of this and other warnings, the U.S. government also announced on Thursday that it would begin to track the risks that these so-called “frackquakes” pose, and start including them on official maps that help influence building codes.
Though the U.S. Geological Survey is known for mapping regular earthquakes and alerting local governments about their risks, it has never taken man-made quakes into account. It made the decision to do so, however, after finding that two strong earthquakes in heavily-drilled areas of Colorado and Oklahoma in 2011 were likely the result of wastewater injection from fracking.
Wastewater injection is not the only thing connected to what the USGS is now calling “induced” earthquakes, however. Gail Atkinson, an earthquake scientist at Western University in Ontario, told the Christian Science Monitor on Thursday that the actual process of extraction from fracking could be causing the quakes as well. Fracking is uniquely characterized by its process — injecting high-pressure streams of water, chemicals, and sand into underground rock formations, “fracturing” the rock to release oil and gas. This could also trigger the quakes, Atkinson said.
“Waste water is the dominant cause,” she said. “But what we are seeing as time goes on is that there are also events being induced from hydraulic fracture operations.”
Thursday’s warning is just one more bullet on a list of scientific papers warning of fracking-induced quakes. Researchers at Southern Methodist University, for example, recently linked a string of 2009 and 2010 earthquakes in Texas to the injection of fracking wastewater into the ground. In early 2013, fracking wastewater disposal was also linked to the 109 earthquakes that shook Youngstown, Ohio in 2011 — an area that hadn’t ever experienced an earthquake before an injection well came online in December 2010.
Related Article: The Fracking Revolution: Promise and Perils
Despite the research, many involved in bringing fracking operations to fruition in some of the more earthquake-ridden places don’t believe a link exists. After experiencing more than 30 small earthquakes in three months, residents of the north Texas town of Azle in January travelled three hours to a Texas Railroad Commission meeting in Austin, urging commissioners to halt the use of the wells.
Texas Railroad Commission Chairman Barry Smitherman, however, refused to acknowledge a connection.
“It’s not linked to fracking,” he said at the time. “If we find a link then we need to take a hard look at all these injection wells in this area. Reexamine them … Perhaps there something that we’re not aware of underground.”
By Emily Atkin