Fracking Open the Earth
Friday, September 2nd, 2011
By Barb Adams
GCN Live.com
The practice of fracking has come under scrutiny due to concerns about environmental and health issues.
Hydraulic fracturing, commonly called fracking or hydrofracking, is the highly controversial process of fracturing rock layers using pressure from a fluid injected into the rock (typically a slurry of water, proppants, and chemical additives) in order to obtain and increase extraction and recovery of oil and natural gas. The practice of fracking has come under scrutiny internationally due to concerns about environmental and health issues, and has been banned in many countries. http://en.wikipedia.org/wiki/Hydraulic_fracturing
The recent 5.8-magnitude earthquake on the East Coast that occurred near Mineral, Virginia, was felt in more than a dozen states and several Canadian provinces. The U.S. Geological Survey (USGS) http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/se082311a/#summary revised their data to indicate that the quake was at a depth of around 3.7 miles, and that the quake’s epicenter was located in an area with limited seismic activity.
The area where the quake was centered is rich in natural gas, and is heavily covered with drilling sites. The gas is buried beneath a layer of impermeable shale known as Marcellus Shale, making drilling of gas wells difficult. Since 2009, however, fracking has been used to access the gas trapped beneath the shale. Using wastewater and high pressure to fracture the shale, the natural gas escapes upwards and is captured. The problem with using this method, however, is that it can cause rapid drops in the rock layers which, in turn, may cause a seismic event. Such was the case in West Virginia in 2009. http://www.dailykos.com/story/2011/08/24/1010047/-was-the-August-23rd-Earthquake-Man-made
West Virginia was a state with minimal seismic activity until fracking began in 2009. The state then began to see an increase in seismic activity, with 2.2 to 3.4-magnitude tremors reported. Officials associated with the drilling processes were quick to dismiss any connection between fracking and seismic activity; however, the coincidence of the startup of fracking practices and sudden earthquakes in a seismically quiet area is notable.
Similar occurrences have been reported elsewhere. In Arkansas, earthquakes began when fracking practices were initiated. And near Basil, Switzerland, a 3-mile-deep well was drilled into a geologically quiet area. Almost immediately, a 3.4-magnitude earthquake occurred. The Swiss were quick to make a correlation, and immediately shut the well down.
Drilling officials in the U.S. claim there is no correlation between drilling and seismic activity, however, the USGS notes that 90% of these shallow quakes since 2009 have happened within 6 kilometers of fracking sites. The USGS also reports that “Earthquakes induced by human activity have been documented in a few locations” and that “the cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil and gas.” Although most of those earthquakes were considered minor, a 5.5-magnitude quake near Denver, Colorado, in 1967 “resulted from fluid injection at the Rocky Mountain Arsenal.” It is important to note that injection had been discontinued in the year prior due to the link made between the fluid injection and earlier earthquakes. http://en.wikipedia.org/wiki/Hydraulic_fracturing
In response to the possible link between hydraulic fracturing and earthquakes, the West Virginia Oil and Gas Commission has forced disposal drilling companies to cut back on water injection rates and pressure. Interestingly, earthquakes have virtually dissipated. And Arkansas has gone even further by placing a moratorium on fracking to study whether there is a correlation.
In Virginia, however, a Texas company has applied for permits to frack in Rockingham County, just two counties away from where the recent earthquake was centered. That area is composed of phyllite bedrock, which is very soft and does not have the ability to sustain fractures under the pressures that exist below the surface. http://www.dailykos.com/story/2011/08/24/1010047/-was-the-August-23rd-Earthquake-Man-made
So is there a correlation between hydraulic fracturing (fracking) and earthquakes? Although there seems to be substantial evidence, more studies need to be conducted; however, the following have been noted: (1) quakes happen in stable areas once fracking occurs; (2) when fracking is discontinued, quakes diminish; (3) the area near the epicenter of the August 23rd earthquake in Virginia has active drilling activity; and (4) another earthquake was reported that same day, almost simultaneously, in southern Colorado at virtually the same latitude as the one in Virginia, in an area with heavy mining and drilling activity.
But perhaps the “best evidence” is the sudden increase in television advertising by Exxon Mobil regarding fracking (watch Exxon’s “Hydraulic Fracturing: How it Works” ad here ) as being safe and insuring us that it is in “our best interests.” Exxon Mobil has just reached a deal with Russia to tap into the Arctic in exchange for training their state-owned oil company on the practice of fracking. Let’s hope they don’t end up fracking the Earth wide open.
http://www.gcnlive.com/wp/2011/09/02/fracking-open-the-earth/
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