Scientists aren't willing yet to say if there is a connection
between a series of nine small earthquakes near Youngstown, Ohio, and hydraulic fracturing. That's the technique nicknamed "fracking," which injects millions of gallons of water under pressure to break up rock and get at fossil fuels, especially natural gas.
It's been used for decades but has expanded in recent years into new territory as natural gas is ever-more touted as a cleaner option to coal and a means to more "independence" from foreign sources of fossil fuels. Some European countries are also adopting or thinking of adopting it to get at their own gas reserves.
Large amounts of water or other liquids can induce earthquakes by lubricating rock layers along fault lines. One notorious instance occurred at the Rocky Mountain Arsenal in Denver in the 1960s, when hazardous waste liquids were injected into a disposal well. Several significant quakes were tied to the process, and they ended when it did.
But geologists definitely don't believe fracking was the culprit in the case of last month's biggest Oklahoma earthquake ever recorded. At 5.6 magnitude, it was too big to have been triggered by the amount of water injected by fracking, said the experts. Kossack FishOutofWater, with a relevant doctorate, went in-depth on the subject in a post last month. He thinks injection of waste water from oil and gas operations was "likely" at fault, a consequence of "induced seismicity." But that's a different process than fracking.
But what of the smaller tremors? In Oklahoma, Texas, Arkansas, British Columbia and elsewhere that possibility is still being explored. Cuadrilla Resources, a British corporation conceded last month that its operations near Blackpool in northwest England had set off three small quakes in April from pumping pressurized water into rock three kilometers underground. It said, however, the quakes were unlikely to be repeated because safer methods will be used in the future.
Not surprisingly, the U.S. gas industry says it sees no conclusive connection. But, as with aerosols powered by cholorfluorocarbons, dioxins and just about everything ever invented that was eventually proved to have unpleasant or disastrous consequences, the companies involved in making or using the products are the last to come around. And then, typically, only after getting their arms twisted. If a quake-fracking link can be established, it would add to worries about the impact of the growing use of the technique. Also on the list of those worries is groundwater contamination, something the industry says it is careful to avoid and environmentalists say may already be happening.
About the Youngstown-area quakes, Henry Fountain wrote:
Nine quakes in eight months in a seismically inactive area is unusual. But Ohio seismologists found another surprise when they plotted the quakes’ epicenters: most coincided with the location of a 9,000-foot well in an industrial lot along the Mahoning River, just down the hill from Mr. Moritz’s neighborhood and two miles from downtown Youngstown.
At the well, a local company has been disposing of brine and other liquids from natural gas wells across the border in Pennsylvania—millions of gallons of waste from the process called hydraulic fracturing that is used to unlock the gas from shale rock.
The location and timing of the quakes led to suspicions that the disposal well was responsible for Youngstown’s seismic awakening. As the wastewater was injected into the well under pressure, the thinking went, some of it might have migrated into deeper rock formations, unclamping ancient faults and allowing the rock to slip.
Scientists say the likelihood of that link is extremely remote, that thousands of fracking and disposal wells operate nationwide without causing earthquakes, and that the relatively shallow depths of these wells mean that any earthquakes that are triggered would be minor. “But still, you don’t want it to happen,” said Mark Zoback, a geophysicist at Stanford University.
Remote? Maybe. Some may be soothed by industry PR proclaiming: "A comprehensive set of federal, state, and local laws addresses every aspect of exploration and production operations." But that's just the standard boilerplate. And bogus. While ground and surface waters are protected from fracking by rules enforced by the Environmental Protection Agency (or states operating under agreement with it), there are no rules governing seismic impact.
[Update]: A h/t to ek hornbeck for pointing to this article in Nature, which reports on U.S. Geological Service scientists who say the size of possible fracking earthquakes are predictable but not how likely they are to occur in a specific case.