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Seismological Society of America Claims Fracking Reactivated Ohio Fault
eldavojohn writes There have been suspicions that fracking has caused minor earthquakes in Ohio but last year seismic data recorded by the Earthscope Transportable Array was analyzed by the Seismological Society of America using template matching and has resulted in a new publication and press release making the statement that Hilcorp Energy's fracking in Poland Township in March of 2014 "did not create a new fault, rather it activated one that we didn't know about prior to the seismic activity." The earthquakes occurred in the Precambrian basement and lead the researchers to posit that further unknown faults may be activated by fracking. The press release ends with urging for "close cooperation among government, industry and the scientific community as hydraulic fracturing operations expand in areas where there's the potential for unknown pre-existing faults."
Don't the mini quakes release energy from the faults more safely?
mini quakes along active fault lines release pent-up energy that protects against "the big one" -- but a dormant fault is like a healed over fracture in your bone -- if nothing disturbs it, it will continue to heal over. Now that it is active again, this will cause a chain reaction of stresses that will likely have continental and possibly global consequences, as it changes the way the other faults interact with each other.
Basically, it made all the related fracture lines that much less predictable.
This is basic high school physics. Energy cannot be created or destroyed, it is conserved. If the amount of energy the fracking put into the ground was less than the amount of energy released from the earthquake, then clearly there was another source of that excess energy. Mainly, tectonic movements had built up stresses into the ground, which would have eventually been released as a natural earthquake if there had been no fracking.
Active fault lines are good. It means tectonic stresses are being regularly released. Inactive fault lines can be good or bad. If there are no more tectonic stresses being built up, then the fault can't cause an earthquake, and it's good. But if there are tectonic stresses being built up, then it's bad because it means that energy isn't being released at regular intervals. We just think it's inactive when it's really not, and it's going to cause a big doozy of an earthquake in the future.
Since the fracking triggered an earthquake, clearly there were stresses in the "inactive" fault, and the fault was of the latter type and thus not truly inactive, and the fracking merely relieved the stress. Basically, if a fault line can be "reactivated", then it was never really an inactive fault line in the first place.
There are some macro (continental-scale) arguments that can be made about plate movements and whether the overall rate at which the plates move (and thus build up stresses in the rocks) can be affected by deliberately relieving some of those stresses (e.g. fracking). And thus fracking could be bad because it increases the rate at which the plates move, and thus increase the rate at which stress builds up and earthquakes happen. But on the local level, the basic jist of the argument that fracking merely triggers earthquakes which were going to eventually happen anyway is correct. Anybody who understands high school level physics can see that.