As our avid blog followers are aware, we keep a close watch on developments in the hydraulic fracturing, or “fracking,” space. One area we have monitored closely is developments in the science around any link between fracking operations and earthquakes. For example, see our recent posts here and here. It should come as no surprise that the science examining any link between fracking and earthquakes continues to develop. Adding to the mix, a Miami University study recently linked a magnitude 3.0 earthquake in Poland Township, Ohio to fracking along an unknown fault line.
As reported Monday, the study was conducted by researchers at Miami University in Ohio and published in the Bulletin of the Seismological Society of America, a peer-reviewed geology journal. As part of the study, the authors looked for any correlation between fracking activity and earthquakes in the area of Poland Township by reviewing seismic data and comparing identified earthquakes with well stimulation reports from the state. They found that a 3.0 earthquake near Poland Township coincided temporally and spatially with fracking along a previously unknown fault line. The authors also identified a total of 77 earthquakes with magnitudes from 1.0 to 3.0 between March 4 and 12 in the same area.
The risk of unknowingly drilling near a fault line is unlikely to go away any time soon. As one of the study’s co-authors stated, “I don’t think there’s a cost-effective strategy or technique to be able to deduce where those faults are in advance.” That said, the authors emphasize that geological due diligence, including increased monitoring of seismic activity, could help prevent earthquakes near fracking sites. As one study author put it, “The point I would want to sort of shout is: ‘Hey this is rare, but looks like we could employ some techniques to help regulation to help prevent cases like this.'” Ultimately, the authors advocate an information-sharing and monitoring partnership between the industry, regulators and environmental groups.
On the heels of the earthquake study in Ohio, it was also reported that the State of Kansas has installed seismic monitoring stations in south-central Kansas to monitor increased earthquake activity. The monitoring stations are part of a seismic network funded by the state in November as part of the “Kansas Seismic Action Plan” developed by the three-member “Induced Seismicity Task Force.” The U.S. Geological Survey documented approximately 124 earthquakes in Kansas in 2014, while there were only 32 in 2013, and none in 2012. The report notes that while fracking has often been blamed for the increase in seismic activity in Kansas, the U.S. Geological Survey has stated there is “no evidence to suggest hydraulic fracturing itself is the cause of the increased rate of earthquakes.” It goes on to note that a more likely cause may be wastewater from fracking operations that is injected into disposal wells. This “fluid injection can increase underground pressures, lubricate and weaken faults and, in some cases, cause earthquakes.” So far, the Kansas Induced Seismicity Task Force has stated that it has no conclusive evidence linking fluid injection to specific seismic events in Kansas.
It was also reported that seismologists will install more measuring equipment Monday in the Dallas suburb of Irving, Texas. This was spurred on by an increase in earthquakes in the area in the past year–approximately 16 since October, including one with a 3.3-magnitude. The report also notes that seismologists are examining earthquakes near the city of Azle to see if they are linked to disposal wells. And, in neighboring Reno, disposal well operators must prove injections will not cause earthquakes before receiving city permits.
All of this shows that hydraulic fracturing continues to be intensely scrutinized.