In last week’s column, I noted that some estimates for the recent earthquake in Athens County indicated it originated too deep in the Earth’s crust for human activities to have been a factor. According to the United States Geological Survey (USGS), the depth was 7.9 km, and this was the figure cited in the Nov. 21 article in The Post. So far, the story adds up.
But it doesn’t hold up for long. What I had not realized was that this estimate of the earthquake’s depth did not include the very significant range of error involved: +/- 7.8 km. This is a range of error almost as great as the estimate itself, and it means that the USGS’s own calculations suggest the earthquake could have begun only 0.1 kilometers from the surface. Calculations of the depth may have been assigned based on insufficient data, as indicated by the extremely high range of error, and the fact that the estimate falls within the 5-10 km range typically assigned to the depths of mid-continent earthquakes, for which not enough information is available. In either case, use of USGS figures to rule out human involvement in the earthquake is unwarranted.
I would like to thank Heather Cantino of the Athens County Fracking Action Network for corresponding with me on this topic. If you are not a supporter of the Athens County Fracking Action Network yet, the article ‘Potentially Induced Earthquakes in Oklahoma, U.S.A.,’ published in Geology in June 2013, may make you want to ask where you can sign up. This peer-reviewed publication concluded that a November 2011 earthquake with a 5.7 magnitude that destroyed 14 homes in Oklahoma could be linked to three fracking wells in the vicinity, placed at depths between 1.12 and 1.8 km. It is the arguably largest earthquake attributed to fracking to date, and indicates that earthquakes due to fracking are, clearly, not inherently harmless.
The same piece also states that the number of earthquakes with a magnitude of five or greater increased 11 times over between 2008 and 2011, compared with 1976-2007. Though I could not find any figures on increases in fracking for the same years, the fracking boom is, as far as I can tell, the main change that has taken place in the Earth’s crust during that three-year period; other than that, geology doesn’t change much from year to year.
Our recent local earthquake may have been due to fracking. It was near an abandoned injection well, which may have lubricated the fault line; it was near the construction on the Nelsonville bypass, which altered the amount of pressure on the underlying layers of rock; and its depth cannot be determined. My original dismissal of the idea that the earthquake was caused by fracking was premature and probably unfounded. It must be investigated further. And whether it was due to fracking or not, there is good reason to avoid the practice, follow the cautionary principle and not grant permits for further drilling in Athens County.
Zach Wilson is a senior studying philosophy. Do you support rejecting all applications for fracking permits in Athens County? You can tell him at cw299210@ohiou.edu.
