QUAKE CAUSE?: Oklahoma recently experienced its strongest earthquake ever, and some suggest drilling for oil and gas may have played a role.
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The biggest earthquake ever recorded in Oklahoma struck on November 5, a magnitude 5.6 temblor that buckled a highway and ruptured water pipes. This quake is part of a skyrocketing rise in seismic activity the state has seen in the past three years, leading many to wonder—and worry—about its cause. Might the practice of fracking, a controversial method of fracturing rock to help get at fossil fuels, be to blame?*
The earthquake struck around 10 P.M. local time about 50 kilometers east of Oklahoma City, and was felt from Saint Louis to Dallas. Until then, the state's largest temblor was a magnitude 5.5 event near the town of El Reno in 1952.
Overall, only minor injuries and damage were reported after last weekend's earthquake. A magnitude 4.7 foreshock preceded the quake by about 20 hours, and dozens of aftershocks were detected as well. These all apparently happened on the well-mapped Wilzetta Fault. "It seems the east side of the fault moved a bit southward," says seismologist Randy Keller, director of the Oklahoma Geological Survey (OGS).
The recent uptick in the area's temblors has been dramatic. From 1972 to 2008 only two to six earthquakes were reported per year in Oklahoma, and were often too small for people to notice. However, in 2009 nearly 50 earthquakes were recorded (pdf), and that number more than doubled in 2010 to 1,047, with 103 powerful enough to be felt.
This unusual seismicity has led some to wonder about increased activity in the area related to fracking, or hydraulic fracturing, which uses millions of gallons of fluid to break apart rock and release natural gas. The practice generates a considerable amount of waste liquid, which is often disposed of by injecting it into deep rock formations where it can lubricate faults. Hydraulic fracturing is common in Oklahoma, the nation's third-largest producer of natural gas, and has taken place there for decades (pdf). Now, with the discovery of natural gas deposits in other regions of the U.S., the extraction method is being used more widely and has raised concerns about its potential to contaminate drinking water.
Fracking has been linked to two minor earthquakes in northwest England, very likely by lubricating an already stressed fault zone and thus making it easier for the land to shift (pdf). A report in August (pdf) by seismologist Austin Holland at the OGS also suggested that a swarm of nearly 50 small quakes of magnitude 1.0 to 2.8 near the center of the state might have been triggered by nearby fracking.
Still, researchers say it seems unlikely that fracking had anything to do with last weekend's magnitude 5.6 quake. "There was a lot of deformation of the Earth here 300 million years ago that created huge geological structures in the subsurface that shift from time to time," Keller says. "We have an unstable situation here, and it's one reason why oil and gas is available here in the first place."
"I won't say that man's activity never ever caused the release of seismic stress, but hydro-fracks are such small things," Keller adds. "If we were talking a magnitude 1 or 2 earthquake, that'd be different, but it's awfully hard to imagine a hydro-frack being involved with one of this size. We also have to determine if there were any frack jobs going on there right now, but I don't think there were—it didn't happen in an area of particularly active oil and gas exploration."
As to whether the spike in earthquakes recently seen in the state might be due to fracking, "it is probably best not to attach much significance to perceived increases in seismic activity in Oklahoma—the occurrence of earthquakes anywhere is quite irregular," says seismologist Art McGarr with the U.S. Geological Survey. This surge in quakes might be a temporary statistical anomaly.
"It may be, however, that more earthquakes are being induced in Oklahoma because of an increase in disposal well operations and, indeed, research is going on now to investigate this possibility," McGarr says. The large amounts of fluid disposed of in this way can seep into cracks and lubricate already stressed faults, making it easier for them to slip and cause an earthquake." No answers yet, however."
Scientists had three or four seismographs positioned at the epicenter of the earthquake when it occurred, and another 25 to 30 will be deployed there now or soon to study aftershocks and locate the November 5 quake's origin more precisely. "In a few weeks or a month we may have a better idea of what might have caused this earthquake sequence—natural tectonic processes or industrial activities," McGarr adds.
*Clarification (11/15/2011): This sentence was edited after posting to describe the fracking process more precisely.
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19 Comments
Add CommentIf fracking lubricated a stressed zone sufficiently to cause a quake, it is important to remember that the stress itself was already present. The released energy of the earthquake was already present, and was going to slip at some point. Very likely the release would have been even larger. Still, considering the already-controversial nature of the procedure, it would be prudent to study the effects of fracking on earthquakes.
Reply | Report Abuse | Link to thisIf the oil/gas industry is interested in looking for an 'upside' to polluting water supplies, they may have found one. After all who knows... They may have theoretically saved the people of Oklahoma an earthquake in the far future. The reality is however, that NO scientific basis exists for 'stress relieving fractures'.
Reply | Report Abuse | Link to thisThe title of this article "Did Fracking Cause Oklahoma's Largest Recorded Earthquake?" is actually a clear sign that this 'news' is simply spin control. The story behind the story is that people are being poisoned in the name of profit, regardless the author attempts to divert you with the 'news' that the process could relieve pent up earthquake stresses in the ground.
People wont have their health or beautiful land, and their aquifers will be needlessly poisoned. Land values will be depreciated. These health and value issues with your land you worked hard to own and preserve seemed to be secondary to theories from seismologists who will probably be noted for being biased to the oil/gas industry.
Why is this all happening? Corporate greed by corporations, they've creating fear about oil sustainability, and they have manipulated law. Powered by lobbyists of the oil/gas industry. Actual evidence exists of this.
Fracking is sending us and our families into a clear path of unhealth, and on some level exposing us to financial liability with depreciated land values due to creating these toxic waste dumps.
Sick of it are you? Keep reading, create awareness of the simple truth, and keep looking for (other) articles with a scientific basis, not just 'prettied up' spin control.
Why is "all this" happening you ask? Corporate greed is your answer along with a few other shallow platitudes.
Reply | Report Abuse | Link to thisActually the reason "all this" is happening (and by "all this" I mean the use of fracking to exploit energy resources) is that people demand gas and the products which are derived from gas. Producers respond by obtaining gas by the most economical means legally possible. It's called commerce and the law of supply and demand. It's not caused by greedy corporations. It doesn't affect the beauty of the land, the value of the land or the aquafiers when compared to conventional gas drilling. And it doesn't cause earthquakes.
I suppose the time has come when we are forced to set a legal limit on the size of earthquake one should be allowed to create.
Reply | Report Abuse | Link to thisSimply saying 'no you're wrong' isn't really useful in a forum like this. Consider fact-based statements instead.
Reply | Report Abuse | Link to thisYes indeed supply and demand is the vehicle that facilitates actions like drilling for oil and gas - everybody gets that. That doesn't need to be presented as an original concept.
One could ask, If we were to get natural resources, why do it in such a destructive way? Or is that too trite of a statement as well?
You also have to include the distortion of the Free Market caused by the exemptions from the Clean Water Act and Clean Air Act than drilling companies enjoy. Since other corporations and activities have to abide by the existing laws while fracking gets a pass, the Market is operating sub-optimally. In addition, since natural gas is being made artificially cheap by these political favors, other energy sources are being undercut by forces external to the Market.
Reply | Report Abuse | Link to thisI guess you completely ignored this passage, "Fracking has been linked to two minor earthquakes in northwest England". But I know you'll explain that away as those darned scientists trying to expand their Socialist agenda or something rather than admit you are wrong. You know, if I can light my tap water on fire and the property experiences a 25,000% increase in earthquakes in the last two years, you're delusional to think that this won't affect the price I could sell it for.
brainjack, This is a classic case of danged if you do and danged if you don't. To some on the far right even raising the question is a sure sign of the liberal bias while others on the left aren't happy with the conclusions when they don't get the answers they are wanting to see. This article was narrow in scope, was fracking responsible for the Oklahoma quake, and was not supposed to be a comprehensive article on the overall effects of fracking.
Reply | Report Abuse | Link to thisThe "big earthquake" is an asteroid hit.There won't be a debate about that, if it happens. I better buy some mid - ocean real estate. before it pops up.
Reply | Report Abuse | Link to this"Actually the reason "all this" is happening (and by "all this" I mean the use of fracking to exploit energy resources) is that people demand gas and the products which are derived from gas"
Reply | Report Abuse | Link to thisNo, it is not only the consumers who drive demand and supply.
"Producers respond by obtaining gas by the most economical means legally possible"
Producers do not always use only legal means. This is why we have regulations, oversite, and consequences.
"It's called commerce and the law of supply and demand"
If the "law" exists it is a complex law. Market forces are not only positive. For example fraud is a market force and the supply of a product can be controlled and its demand can be manipulated.
"It's not caused by greedy corporation"
Greed is another market force.
"It doesn't affect the beauty of the land, the value of the land or the aquafiers when compared to conventional gas drilling"
So it does negatively affect the beauty of the land, the value of the land or aquifers
"And it doesn't cause earthquakes"
I agree, earthquakes don't have unique causes.
Nikola Tesla caused world record 47ft uplift earthquakes in Alaska September 1899 and I can mathematically prove Earthquakes have been CAUSED. BET?
Reply | Report Abuse | Link to thisSure, tell us all about what Nikola Tesla did.
Reply | Report Abuse | Link to thisWhat evidence can you provide to warrant your claim?
Reply | Report Abuse | Link to this"Very likely the release would have been even larger," writes mgollery.
Reply | Report Abuse | Link to thisThis "very likely" will never be proven true or false statement. I would venture that the opposite could be true or the release of energy could be the same. But also, the quake might have not have taken place within the lifetime of a 1000 people had the fault not been lubricated-the TRUTH is it is unknowable - the point I am trying to make. Of course unless you have some info which could be useful in predicting earthquakes and severity which the scientific community does not have?
I also question the validity of the statement regarding consumerism as a market driver...i would suggest if the oil and gas LOBBY were not such a major player in our government maybe the consumer (free-maket) might find it is cheaper and more sustainable for our planet to find less toxic means of energy production. I for one would much rather find a more harmonious way for creating wealth than by intentionally destroying planetary features (whether seen or unseen).
Using an argument fracking "looks" nicer than conventional drilling doesn't make much difference to a dying planet.
If we are so sure fracking isn't a cause of earthquakes (big or not) why not frack under a conventional nuclear power plant near your house?
I mean surely its safe...why would the congress give fraking such a unique pass around current regulations because we all want cheap oil and gas and we want clean water...surely a special interest groups as big as exxon-mobile/haliburton/BP can't have more influence on what the market wants than the consumers themselves?
Maybe too, we are given the illusion of choice, no?
"Still, researchers say it seems unlikely that fracking had anything to do with last weekend's magnitude 5.6 quake".
Reply | Report Abuse | Link to thisIn other words they don't have a clue! They don't know how it works, they don't know why it works, they do know however that something happened and something will happen again, will happen again, (built in redundancy) in the future. What that something was has yet to be determined and the something in the future is yet to be disclosed, so in effect... "We dont have a clue" should be the official position.
This should be of concern to us all. As major quakes and volcanos effect the world. But I believe not enough is given to the planets solar alignment. This is causing gravitational pulls and we are flying through the magnetic fields every 24 hours. This must be causing friction and raising the temperature of our planet.
Reply | Report Abuse | Link to thisThe effects of the solar alignment are likely to last for six years. Getting worse in the mean time. With the two combined!
If we break it(The world that is)how do we fix it? We can hardly move next door.
Can we get passed the politics and finger pointing.
We that is everyone can not afford for us to break the planet it's our home. Look at the Bigpicture!
Ooooooooommmmmmmmm.
Reply | Report Abuse | Link to thisI smell lawyers.
.
This article is uncomfortably reminiscent of the studies financed by the tobacco industry which claimed that cigarette smoking was not harmful.
Reply | Report Abuse | Link to thisMr. Choi neglected to mention the number of fracking sites, as well as the amount of - and rate at which - fracking material is injected.
According to testimony by the Oklahoma governor this past week (http://tinyurl.com/82snqer) over 95,000 well sites in the state had been fracked.
According to one article (http://www.lhup.edu/rmyers3/marcellus.htm ) 4-7 million gallons of fracking compound are injected at high pressure into our earth for each site.
Using 5 as a working number, that's about 475,000,000,000 gallons of material, at an injection rate of, "up to 100 MPa (15,000 psi) and 265 L/s (100 barrels per minute)" (http://en.wikipedia.org/wiki/Hydraulic_fracturing).
There is no disputing the number of smaller earthquakes which surround fracking operations. I am certain that many readers would like to see a list of Mr. Choi's referenced seismologists (and their employers) as an addendum to this article.
In a recent related article, seismologist Austin Holland is quoted as having said, ""You have an earthquake that occurs, and that changes the stress ever so slightly next to it, and so another earthquake occurs, and it's just sort of like a zipper unzipping. It kind of just goes down the line." (http://tinyurl.com/6ufxt2e)
Dr. Randy Keller's statement, "We have an unstable situation here, and it's one reason why oil and gas is available here in the first place," raises a host of other questions.
Leaving the spectre of long-term poisoning of our nation's fresh water to wall street speculators, tree-huggers, and hippie-environmentalists, it would be a pity if Scientific American was discovered to be skewing facts in order to be a public relations venue for the oil and gas industries.
SciAm, where is the hypothesis and scientific method in your article??! You cannot discount your original question without considering many debate angles and multiple sources. It is doubtful that Keller and McGarr represent a full spectrum of scientific analysis/contributors on this topic. Also, given the timeliness of this topic, it may be more appropriate to avoid deriving and stating conclusions in your subtitles until such a time where appropriate scientific information (ie/ data and studies) are available to back up your assertions. Mere speculation is hardly worth reporting, nor scientific.
Reply | Report Abuse | Link to this"There was a lot of deformation of the Earth here 300 million years ago "
Reply | Report Abuse | Link to thisDUH! How about TWO impact craters about 300 million years ago! One 13.5 Miles across the other 66 miles across.
One directly below the major earthquakes. It is about 13.5 miles across. The center is at approximately 35.557N, -96.871W
The upper half of the crater structure under Meeker, Oklahoma is mostly visible on the BLM's topographic display.
It appears that the Impact Crater under Meeker has a much bigger Brother, the Choctaw Crater.
It appears to be about 66 miles across. Center 35.060N, -97.315W
A good view is available at the Bureau of Land Managements site, Google uses a patchwork of pictures from different seasons.
http://www.geocommunicator.gov/GeoComm/lsis_home/townshipdecoder/index.htm
Click on GeoCommunicator PLSS map half way down the page.
UNCHECK Data Download Availability, UNCHECK PLSS
Switch it Topographic mode by using the buttons at the bottom of the page.
The Meeker Crater is East of Oklahoma City. The lower edge is about 8 miles north of Shawnee Oklahoma.
If you have zoomed in so that I-44 and I-40 are barely in the frame. You will see a dashed line running between I-44 and I-40 (Wilzetta Fault Line). The dashed line crosses what appears to be a lake, that lake is part of an arc going slightly north to the left, and slightly south to the right. This is not an artifact, it shows up in the well logs with some displacement. What is visible on the surface is not the actual impact structure. What is visible in the satellite images are the long term effects of the faulting of the sedimentary rock layers that had formed above the structure. As the new rocks were being lain down , they would develop faults as the impact structure beneath them continued to settle. These faults would tend to erode more quickly then adjacent areas. We are probably just seeing the surface shadow of the real crater, which is still 3500 feet below.
The potential Choctaw Crater is visible on the BLM site centered at 35.060N, -97.315W. It actually cuts into the southeast side of Oklahoma City. Oklahoma City is at about the 11 o'clock position of the potential Choctaw Crater. The town of Davis Oklahoma is about 4 miles south of the 5 o'clock position of the Choctaw Crater.
The oil well logs are a mess under the craters.