Evidence against fracking enough to be concerned

(This is the letter that I published in the Marietta Times on 28 Dec 2011. For a more complete update, including further reading, see this blog for 2 Jan 2012)

While researching a possible link between fracking and earthquakes, I found that The Times doubts that such a link exists. In fact, the opposite is true - a link is very likely.

Scientists have coined the term 'induced seismicity' to describe earthquakes caused by human activity. Several examples of earthquakes in the past caused by oil and gas drilling have been documented. These earthquakes can be triggered when water under pressure encounters a fault (i.e., a crack in the subsurface rock, which can be very small or up to miles in extent).

The fracking process produces tiny earthquakes as a side effect of the cracking to release the gas. And oil trapped in the rock. But they are detectable only by sensitive instruments. The question is whether the current technology being used in Ohio can trigger earthquakes large enough to be felt by humans. In order to avoid the possibility of earthquakes, the driller has to be sure that his shaft does not encounter a fault. Unfortunately, the number, size, and location of all faults in Ohio is unknown.

In the first half of 2011, people living in both England and Oklahoma felt tremors. In both places expert analysis has suggested that they were caused by fracking. The second half of 2011 has seen major earthquakes centered in both Virginia and Oklahoma. Activists have claimed that these bigger earthquakes are also caused by fracking, but a good case has not yet been made.

There is also evidence of earthquakes at, or near, fracking-waste-water injection well sites (storage pits). Good evidence for such earthquakes was found near injection wells in Arkansas; there were multiple small earthquakes, whose numbers greatly diminished when injecting liquid into the wells was stopped. Earthquakes near injection wells close to Youngstown in 2011 may have had the same cause. Other suspect earthquakes in 2011 occurred in Marietta and in West Virginia.

All of the events mentioned above happened in 2011. Scientists have been aware of fracking-induced earthquakes for some time, but the public is just starting to become aware of the connection. While the evidence may not be solid enough for a court of law, there is enough evidence for serious concern.

Several organizations, including the League of Women Voters of Ohio, have called for a moratorium on drilling. Clearly a pause is needed until the geological faults in Ohio have been mapped. Otherwise a deep hole will be drilled into an earthquake fault and filled with water - actions that can trigger an earthquake.

Documentation of the facts in this note can be found on my blog for 23 December 2011.

Alan R. Rosenfield, ScD FASM

Columbus