Tearing rocks apart under your feet with chemicals seems like exactly the kind of thing that would cause the ground to be unstable – and maybe lead to something like earthquakes if it was on a large scale – doesn’t it? Despite the fact that it sounds like the most obvious plot to an environmental disaster novel, fracking is very real and has defenders and lobbyists that insist upon the lack of definitive evidence on its adverse planetary effects.
That definitive evidence may have recently been released, as researchers have claimed that the technique used to extract natural gas can be directly linked to nearly 80 earthquakes in Ohio in March 2014. Some earthquakes reached up to a 3.0 magnitude.
Fracking involves cracking shale rock in order to access the fossil fuels that are trapped inside. A pressurized mixture of water and chemicals is pumped into the fractures to force the desired substances to come to the surface. On their own, the chemicals are said to be harmful enough. When introduced at the depths where fracking occurs, there are concerns that they can pollute water tables and damage soil.
Robert Skoumal, author of the paper linking Ohio’s earthquakes to fracking, pointed out that a 3.0 magnitude quake is minor when compared with some of the more serious quakes that have hit regions such as California and Japan. Skoumal also noted that by continually breaking rocks at the depth of the Precambrian basement, this produces “micro-seismicity.”
“These events are extremely small, often between magnitudes of negative three and zero, no greater than magnitude one,” he stated. “This seismicity is expected and normal. The process of hydraulic fracturing causing a pre-existing fault nearby to move is very abnormal.”
Yet California and Japan both lie on actual tectonic fault lines, where the earth’s tectonic plates shift against one another. When you think about it that way—that the fundamental layers of the earth are crashing against each other—earthquakes are a completely understandable result of such seismic friction.
Ohio, however, is in the middle of the North American plate. So to compare California and Japan to Ohio is misleading because they share very little in terms of tectonic properties.
Last week, Skoumal fielded questions on his research in a Reddit AMA. One commenter asked if Oklahoma would be the next study for Skoumal and his associates, adding, “I remember when nobody had ever felt an earthquake, now we’re all veterans.”
Last August, Oklahoma recorded 20 earthquakes in less than 24 hours. Since fracking operations began in the state five years ago, Oklahoma has experienced over 2,500 small earthquakes. Prior to hydraulic fracturing, Oklahoma recorded just one earthquake between 1978 and 2008.
Another Redditor asked Skoumal to “Please look into all the activity we have had in DFW, Texas. Seismically this area has been dormant all my life but a few years after the fracking boom we started having quakes. It’s pretty clear that they are related to the fracking that is going on but it’s been such an economic boom that everyone just wants to stuff their fingers in their ears and pretend like it isn’t happening.”
According to Skoumal, the study did not use any industry data sets, but rather seismic data from free, publicly-available sources online (accessed through IRIS). A large portion of this data came from the USArray and OhioSeis.
But the 3.0 quake last march caught the attention of the Ohio Department of Natural Resources, a government agency that regulates gas and oil extraction in the state. The agency subsequently told energy exploration company Hilcorp to halt drilling a new well close to the earthquake’s epicenter—one of six wells the company has in the area. Hilcorp representatives said they wanted to review the full report before commenting.
The largest earthquake to hit Ohio since 2010 was a 4.0 magnitude quake in Youngstown in 2011. Skoumal and his colleagues linked that one to wastewater injection, when the leftover water used in fracking is inserted into nearby wells.
It seems that the damage will not be irreversible if these extraction processes are stopped. According to Skoumal, “There is no evidence to suggest that earthquakes induced by hydraulic fracturing pose long-term hazard to residents. In the Poland Township case, shortly after the operation was ceased, earthquakes stopped soon after. No earthquakes have been identified by us in the area since then.”