By Jillian Kay Melchior
Wednesday, January 21, 2015
Even the authors of the fracking-earthquake study think
the reaction to it has gotten out of hand.
Despite the sensationalistic headlines and opinion
pieces, fracking can trigger earthquakes only in very rare, very specific
conditions, say the authors of the highly publicized study in this month’s
Bulletin of the Seismological Society of America.
“It did seem like there were some folks who were trying
to use this [study] as fuel to say we should ban fracking because it generates
earthquakes,” says co-author Mike Brudzinski, a professor of seismology at
Miami University in Ohio. “But earthquakes’ occurring during fracking is
extraordinarily rare.”
Robert Skoumal, the primary author, tells National Review
Online that he was concerned about the response as news of the report went
viral: “Millions of people saw this [study], and the comment section was just a
train wreck. People didn’t really see what we were doing, what we were arguing.
. . . These are pretty small events, so an outright ban [on fracking] wouldn’t
be appropriate.”
Skoumal and Brudzinski used a computer program coded
in-house to correlate seismic activity and active fracking operations over
time. Using high-tech seismic monitoring, they identified 77 small quakes near
fracking sites around Poland Township. The largest was magnitude 3. “They say
if you’re right on top of it, it’s like a milk jug falling off a counter, and
that’s it,” says Eric Heis, a spokesman for the Ohio Department of Natural
Resources, of this size quake. “A 3.0 is not a danger to anybody. It doesn’t
even knock over a plate on a table,” he added.
Skoumal and Brudzinski tell NRO that the Poland Township
scenario they recorded was freakish. Fracking had occurred right on top of
small, preexisting faults, and shortly after fracking stopped, so did the
quakes.
“In this case, there’s no evidence of wrongdoing by the
operators of this well,” Skoumal says. “They just happened to be operating near
a fault that’s very hard to detect. The conditions were ideal. They were just
very unfortunate in this case.”
Brudzinski insists that, while there are hundreds of
thousands of fracking sites worldwide, “just a handful” have ever been recorded
to trigger quakes. (Another earthquake expert, Cliff Frohlich, tells NRO that
he is aware of “maybe ten other instances on the planet” where fracking
triggered an earthquake.)
“These seem to be very specific situations, and it seems
to be only when you’re very close to one of these faults that’s sort of ripe.
You could have many, many operations where you see no seismicity at all with
fracking,” Brudzinski says. “The fracturing process itself rarely produces
earthquakes.”
The earthquakes that Skoumal and Brudzinski recorded
correlated with fracking operations less than half a mile from the fault.
Around a hundred other fracking sites operated just a bit beyond the half-mile mark,
Brudzinski says, and “they didn’t produce any recordable earthquakes.”
The higher earthquake risk actually involves what happens
after fracking, Brudzinski says. Some companies pump the wastewater back
underground, which can lubricate stone-on-stone stress, unleashing a pent-up
earthquake. “To help you understand the rock-on-rock [tension], think of it as
a really rough surface, almost like it has teeth,” he explains. “In a regular
earthquake, basically, the stresses on both sides of the fault have to be big
enough to break the teeth. . . . But if you put water in there, the two sets of
teeth don’t have to touch and can slip.”
There’s a much stronger correlation between this
wastewater-disposal process and earthquakes, but calling it “fracking” isn’t
accurate, according to Brudzinski.
The appropriate response to their study, Skoumal and
Brudzinski say, is not to ban fracking but to do more research and better
monitor where faults might rest. In the rare event that a fracking site sits on
a fault, or if small earthquakes begin in the immediate vicinity, state
officials and energy companies, they suggest, should consider stopping and
moving operations a bit farther away.
“At this point, there’s not a lot of rationale for huge
changes in how the industry is fracking,” Brudzinski says.
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