Is there a Link between Earthquakes and Shale Gas Drilling?

By Samantha Malone, MPH, CPH – Communications Specialist, CHEC, GSPH; DrPH Student, GSPH

While we don’t typically post about earthquakes on FracTracker’s blog, as public health professionals, we should be prepared for such incidents. Apparently, various towns have reported unusual seismic activity near shale gas drilling operations. For example, Residents in Guy, Arkansas are experiencing “swarms” of earthquakes – sometimes at rates of three to four a minute. While this isn’t the first time in history that the town, which sits in the middle of a tectonic plate in the Fayetteville Shale, has had an earthquake, residents cite the natural gas industry as the cause. (The deputy director of the Arkansas Oil and Gas Commission sees circumstantial evidence related to the deep well injection that is occurring there, as well.) The true trigger of these minor earthquakes is the focus of researchers from the University of Memphis and the Arkansas Geological Survey.

A quick Internet search shows that similar speculations about the link between the natural gas industry and earthquakes have been voiced in West Virginia, Texas, and several other states experiencing an influx of deep well injection (a liquid waste disposal system). Is there really a connection between the two? Do the geologic formations that make shale gas drilling possible have higher rates of earthquakes naturally? (Probably not in PA based on the hazard map produced by the USGS.)

The map below from the DataTool shows all of the shale gas plays in the continental U.S. By clicking on the “i” in the gray toolbar and then on a pink region, you can inspect each play. Just click “view” when the pop-up box appears to learn more.
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Presently, we do not have drilling data from the Fayetteville Shale on FracTracker. If any person / organization has already obtained this information and would like to share it, we invite you to upload it onto FracTracker’s DataTool (Registration is required on our site, but at least it is free.)

Here is a quick list of articles from Google Scholar about induced seismicity if you’re interested, and a really interesting documentary website about people who live and work in shale gas plays across the U.S.