Illustration adapted from a photo of the seismograph from Virginia Tech at the time of the August 23 earth quake with a epicenter near Mineral, Virginia. If readers have additional questions, please add them in the comment section and I'll pass them on to Klose. You can read reviews of this piece and/or add your own at NewsTrust.
Life on the internet imitates art
Hurricane Irene, and before that Virginia's August 23 5.8 earthquake with its epicenter only eleven miles as the crow flies from Dominion Energy's North Anna nuclear plant in Virginia--how much more havoc can we expect in the East? On August 23, art --in the form of a 2010 cartoon by Randall Monroe (website, blog)--predicted life: The Twitterverse and other social media spread news the earthquake faster than the quake itself sent out its tremors.
Click on the cartoon and it will appear large enough to read the captions. Unfortunately, this was the only version I could find. And, by the way, Monroe's strip, one of my favorites, comes with a warning:
this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).
Unfortunately, new media can rapidly deploy misinformation
Evidently, poor science writing can also be unsuitable for liberal arts majors. Opponents of fracking were quick to send me (and others) an article attributing the Virginia earthquake to fracking. The author was Stuart Jeanne Bramhall and her article appeared widely: on Alternet, Open Salon, OpEdNews, and her own blog,The Most Revolutionary Act. And the misinformation spread from there, reaching even the news clipping services for the chemical industry.
At least she signed her piece and included links, unlike an the author(s?) of even worse piece syndicated by Reader Supported News from Russia Today.
I still had my doubts and asked my friend Rory McIlmoil (twitter), Project Manager of the Energy Program for Downstream Strategies to weigh in. Rory wrote back,
fracking has been associated with increased earthquake activity in Arkansas and Braxton County, WV. But fracking in no way could have caused the Virginia quake. There's no fracking anywhere near there.
Cut-and-paste, rush-to-publish-and-syndicate "journalism"
While Bramhall's tone seems reasonable, her piece still has a fatal flaw. Consder how she writes:
According to geologists, it isn’t the fracking itself that is linked to earthquakes, but the re-injection of waste salt water (as much as 3 million gallons per well) deep into rock beds.
Braxton County West Virginia (160 miles from Mineral) has experienced a rash of freak earthquakes (eight in 2010) since fracking operations started there several years ago. According to geologists fracking also caused an outbreak of thousands of minor earthquakes in Arkansas (as many as two dozen in a single day). It’s also linked to freak earthquakes in Texas, western New York, Oklahoma and Blackpool, England (which had never recorded an earthquake before).The problem: Branhall failed to interview said geologists about this particular quake.
So what does a geohazard expert say about fracking and the Virginia earthquakes?
According to Christian Klose (website, pictured below in a photograph he provided), while fracking can be associated with earthquakes, global statistics say that the geomechanical effects occur in a radiius of up to to 50 km radius.(That's only 31.068 miles--not the 160 miles cited by Bramhall.)
the processes of injecting fluids deep underground [such as for fracking] can induce and trigger earthquakes of magnitudes greater than 4.5 if a) stress changes due to the injected fluids extend over a larger area and b) fault zones nearby are large enough and favorably oriented to set off earthquakes...As the name says, fracking is a controlled way to destroy intact impermeable rock to make it permeable for gas and fluids to flow. Each fracking indecent is a tiniy-tinty tremor. The goal is, however, to avoid large tremors (earthquakes).He tells me that at 4.5 magnitude, "earthquakes start to get are more or less damaging at that point."
How I learned about my interview source
Alexis Madrigal, who interviewed Klose for Wired in 2007. As someone who doubts the wisdom of nuclear energy and mountaintop removal coal mining, I laughed at Madrigal's imaginative frame for his piece:
In the first Superman movie, supervillain Lex Luthor plans to trigger a massive, California-detaching earthquake by detonating a couple of nuclear weapons in the San Andreas Fault.Another geohazard: mining
Crazy Lex! That scheme never would have worked, geologists will tell you. But, if he’d been serious about creating an earthquake, there are ways he could have actually done it. He would just have to inject some liquid (as some carbon-sequestration schemes propose) deep into the Earth’s crust, or bore a few hundred thousand tons of coal out of a mountain.
Mining operations account for bout half of human-triggered earthquakes, according to Klose's research. Madrigal writes about the example of Australia's only fatal earthquake in 1989 . The quake killed 13 people, injured 160, and caused 3.5 billion U.S. dollars worth of damage.
Klose tells me that's currently equivalent currently to $5 billion--equal to 20% of the value of the produced coal and more than the the profit that was made on the coal extracted in the area.
Australia had previously been a "stable area" --one with faults that did not produce earthquakes in the last 10,000 years.
As for mountaintop removal, it's
polluting, however, the question is whether a) there is a fault zone nearby that is large enough to produce an earthquake and greater than a magnitude of 4.5 and b) this fault zone is favorably oriented within the pre-existing tectonic stress field in the crust.And how about the proposed uranium mining in Virginia? Klose tells he needs more information, but that it's
possible but it depends on the geology in each specific mining area (50 km radius).
When stable areas erupt
Klose explained to me that even stable regions--those without earthquakes in the 500 to million year range--are still under stress. That stress will build up and be released during an earthquake at some point.
A "tiny" stress alteration... can set off an earthquake, because such faults are close to failure....
What's tiny? According to Klose, a 1/10th of an atmosphere--which is the pressure equivalent to that exerted by 3'4" of water at 60 degrees F at sea level at the same latitude as Paris.The stress can have natural causes such as tectonic forces or changes on the the surface such as erosion or sedimentation of rivers. But, if
Klose adds that earthquakes in stable regions, for reasons not yet explained, tend to occur at half the depth of what national seismic networks estimate. He adds,human activities are large enough, then they can...trigger earthquakes. [Thus]...stable regions have a higher chance to become active regions due to large-scale geoengineering....
That's why they are so dangerous and can be easier triggered from...[alterations to]the surface of the earth's crust...
Other geohazards: dams, carbon sequestration and drilling
Geoengineering can also include dam reservoir construction (about one-third of human-triggered quakes); injecting liquids into the ground and drilling a gusher dry.
Klose thinks carbon sequestration could generate earthquakes too and worries, according to Madrigal, that sequestration could occur near heavily populated regions.
Unfortunately, coal-fired power plants are closer to cities.
Klose told me more research needs to be done because
There are no experiences and examples so far. Again, besides the used technology of mining, injection etc. it mainly depends on the geology in each specific area (50 km [31 mile]radius.
More information:
USGS, FAQ on earthquakes caused by human activity
Virginia Division of Geology and Mineral Resources, earthquake information page, with useful links
2 comments:
The article does well to include carbon sequestration along with fracking as a potential cause of earthquakes.I would just like to add that many geologists are not as reliably scientific as the one quoted here, since many of them are connected with institutions directly endowed by mining,oil and chemical companies.It would be interesting to see statistics on the percentage that are "company geologists".
Good point. Thanks!
Post a Comment