Due to a lack of juicy evidence that hydraulic fracturing actually harms the environment, the latest argument from the anti-fracking crowd has circled back to the idea that fracking can cause dangerous earthquakes. The debate’s revival is largely due to research presented by Geophysicist William Ellsworth (not yet published) to the American Association for the Advancement of Science that “smaller earthquakes could increase the risk of a larger, more damaging one occurring eventually.
Although one should take any scientific study seriously, it is important to understand its context and application. As the research applies to fracking, consider the following points:
1. Firstly, for intelligent discussion, one should separate conceptually hydraulic fracking from wastewater injection. The former involves perforating rock over a mile beneath the surface to access hydrocarbons, whereas the latter involves disposing wastewater from manufacturing, farming, oil and gas drilling, mining etc., into deep underground wells. Wastewater injection wells are related to earthquakes, the actual technique of hydraulic fracturing is not. It would be a fallacy to blame fracking for causing earthquakes. The focus should be on injection wells.
2. If we move beyond the idea that many smaller earthquakes could cause a larger earthquake, and assume that smaller earthquakes definitely can, we must consider that for smaller earthquakes to pose a hazard, they need to be near major fault lines. A major earthquake does not spontaneously happen–it requires a major fault line. There already are (as there should be) safeguards in place to prevent the drilling of a wastewater injection well near a major fault line.
3. A report published last year in Science by researchers from Cornell, Columbia and UC-Boulder showed that of the 4,500 injection wells in Oklahoma, only 4 (less than 0.1%) produced seismic activity, and these were among the highest volume operations. Clearly the issue is not as rampant as may be assumed by headlines. In addressing concerns, William Ellsworth says “in many of these cases, it’s been fixed by either shutting down the offending well or reducing the volume that’s being produced. So there are really straight-forward fixes to the problem when earthquakes begin to occur.”
When one considers Ellsworth’s research in light of the larger picture, one can see that many headlines decrying fracking are patently false or misleading. It is unfortunate that many media outlets advance sensational and absolutist claims about the nature of hydraulic fracturing, but if one makes an attempt to grasp the larger picture and understand nuance, the truth, fortunately, comes out.