Revisiting the Fracking–Earthquake Connection

Here’s the situation in Texas and other parts of the country where fracking for natural gas has come on the scene: it’s producing a hell of a lot of gas, excitement, and money.

Earthquake epicenters examined in the study (red circles), injection wells (squares and + symbols) in use since October 2006, seismic monitoring stations (white triangles), and mapped faults (green lines). Credit: Cliff Frohlich/U. of Texas at Austin.

All of this gas is also producing a hell of a lot of wastewater, which, according to experts is producing a hell of a lot of earthquakes. Earthquakes? Yes, that’s right, earthquakes, as in the kind that shake the ground. According to some geophysicists, it isn’t fracking itself that’s causing earthquakes, it’s all the wastewater being pumped back into the ground for storage.

One of the most troubling concerns about these man-made earthquakes is the fact that they’re happening in places where people rarely, if ever, noticed them before. Timpson, a small town in east Texas, is a good example. On Friday, Dec. 7 at 1:38 p.m, it was shaken by a 2.8 magnitude earthquake only 5 km below the surface.

Although quakes are almost never felt in this part of the country, Friday’s tremblor isn’t the first this year. A  3.7 magnitude earthquake caught everyone’s attention on May 10, 2012. This was followed by an aftershock on May 17 that measured at a magnitude of 4.3.

Scientists at the Stephen F. Austin Geology Department in Nacogdoches have been monitoring earthquakes in the area to determine their cause. Dr. Wesley Brown, an associate professor in the geology department, thinks the earthquakes are being caused by massive amounts of hydrofracking wastewater being pumped into nearby injection wells.

“At the moment we are actually linking them to injection wells that are located close to where the earthquakes are in the Timpson area. We have one a little bit to the north, and [the wells] are north and south of each other,” said Dr. Brown. “The volume, especially for the one in the south is up over 200,000 barrels of water per month.” 1)

Assuming these are 42 gallon barrels, this equals 8.4 million gallons of water per month.  There are currently over 144,000 injection wells in the U.S. With more than 49,000, Texas holds the majority, by far. 2)

Apart from the soundness of storing highly toxic water in the earth, human activities that create earthquakes pose a number of serious questions. Unfortunately, these questions may be complicated by the vast amounts of money the nation’s fracking currently yields.

The group Texas Natural Gas Now claims that natural gas, much of it captured through fracking, “contributes more than $100 billion to the Texas economy each year, including product sales, royalties, and property, state, local and severance taxes.” 3)

Whether $100 billion outweighs the many costs fracking produces (such as earthquakes) should be seriously examined by federal and state authorities. On the surface of it, it’s apparent that the very process of hydraulic fracturing (i.e., fracking) is an environmentalist’s worst nightmare. It involves drilling holes in the ground thousands of feet deep; dropping and detonating explosives in the holes;  and then pumping in millions of gallons of chemical-laced water (aka “slick water”) to free oil and gas trapped in rock. This process has enabled energy companies to get at oil and gas, which, up until now, has been off limits due to the difficulties involved in obtaining it. Fracking has sparked a drilling boom of staggering proportions in the U.S. and elsewhere.

Though it’s hard to state with precision where millions of gallons of toxic water goes when its forced down under high pressure into a hole thousands of feet deep, it often comes bubbling back up to the surface whence it came. In addition to the chemicals that were added to it before it was originally pumped into the ground, it returns to ground level full of additional extracts and minerals picked up on its journey: salt, heavy metals, radon, etc.

To solve this inconvenience, more holes must be drilled in the ground. These are referred to as injection wells and are designed to hold large quantities of the wastewater. Instead of a few thousand feet, they reach far deeper, often as much as 1 1/2 miles below the surface. The dirty water is pumped back down where, engineers assure us, it won’t escape and contaminate other resources, like, for instance, drinking water.

Whatever your stance on the matter, whether you’re pro-fracking or anti-fracking, the available data makes it pretty clear that a lot of earthquakes are starting to be felt in places where people rarely, if ever, noticed them before.

Before a series of small quakes on Halloween 2008, the Dallas area had never recorded a magnitude-3 earthquake, said Cliff Frohlich, associate director and senior research scientist at the University of Texas at Austin’s Institute for Geophysics. 4)

Frohlich analyzed seismic data collected between November 2009 and September 2011 by the EarthScope USArray Program, a National Science Foundation-funded network of broadband seismometers from the Canadian border to the Gulf of Mexico.

Frolich surmises that pumping millions of gallons of wastewater into the ground can have the unintended consequence of causing fault lines to slip, which can produce earthquakes

“You can’t prove that any one earthquake was caused by an injection well,” says Frohlich. “But it’s obvious that wells are enhancing the probability that earthquakes will occur.” 5)

Other geophysicists seem to think that this explanation makes sense. For example, Oliver Boyd, a USGS seismologist and an adjunct professor of geophysics at the University of Memphis, agrees that, in general, links between wastewater injection and seismic activity are plausible.

“Most, if not all, geophysicists expect induced earthquakes to be more likely from wastewater injection rather than hydrofracking,” Boyd wrote in an email to Life’s Little Mysteries. “This is because the wastewater injection tends to occur at greater depth where earthquakes are more likely to nucleate. I also agree [with Frohlich] that induced earthquakes are likely to persist for some time (months to years) after wastewater injection has ceased.” 6)

As for the fracking itself, Frolich doesn’t believe that it causes earthquakes.

“Drilling never causes earthquakes,” Frohlich said in a telephone interview [with Reuters]. “Fracking almost never causes earthquakes … While there are probably millions of hydrofracking jobs, only a few have caused earthquakes and they’ve all been little tiny earthquakes.” 7)

Assuming the geophysicists are right, the question just screaming to be asked is whether it’s wise to pursue a course of action that causes earthquakes. Why on earth would anyone want to do anything that causes earthquakes? Specifically, should we continue to pump billions of gallons of water into “wells” if it’s possible to cause earthquakes?

But Frolich doesn’t appear to be too concerned.

“It’s not entirely clear to me that you need to stop [the quakes],” Frohlich says. 8)

“My study found more small quakes, nearly all less than magnitude 3.0, but just more of the smaller ones than were previously known. The risk is all from big quakes, which don’t seem to occur here.” [referring to the Barnett Shale.] 9)

StateImpact Texas reports that Frolich compares the experience of feeling the smaller quakes to witnessing a moderate thunderstorm that might wake you up in the middle of the night with a boom. “It’s actually kind of fun,” he says. 10)ibid

Yet, as far as we know, thunderstorms are still produced by nature only; they’re not by-products of profit-driven enterprises.

Moreover, what about the what-if factor? Do we know what all the unintended consequences are of producing artifical earthquakes. After all, the state of Texas isn’t a laboratory. It exists in the real world. And the world is incredibly complex, being composed of untold numbers of interconnected life-forms and systems. To unleash forces huge enough to cause earthquakes is to gamble with complexities which we cannot hope to full understand. For example, what if the quakes get more frequent or worse? Do we know for sure that countless billions of gallons of water won’t cause this to happen?

It’s well documented that quakes caused by injection wells can occur long after injecting the water. The 1961 injection well drilled near Denver is a case in point. According to the USGS 11)United States Geological Survey , “an unusual series of earthquakes”erupted in the area soon after.” A year and a half later, on Aug. 9, 1967, a 5.3-magnitude earthquake, the most powerful in Denver’s history, struck. It was followed by a 5.2-magnitude quake in the region that November, according to the USGS.

The biggest earthquake linked to an injection well occurred in Oklahoma last year. It was a magnitude 5.7.

Slick-water fracks were first introduced in the Barnett Shale field, which is a region in Northern Texas that encompasses the Dallas-Ft. Worth metropolitan area. The number of wells drilled in the area went from a yearly average of 73 in the late 1990s to 2,500 in 2007.

As of January, 2012, the Railroad Commission of Texas reports that there were 14,661 producing gas wells in the Barnett Shale 24 county area. 12)

A database search in the Advanced National Seismic System reveals that from January 1, 2000 – January 1, 2006, no earthquakes  were recorded in the Barnett Shale region and east Texas (where a number of injection wells have been drilled). But from Halloween 2008 to the present 59 quakes were recorded (though Frolich’s study found 68 from 2009 – 2011). 23 of these occurred in 2012 alone. The average magnitude was 2.6 and 15 of them registered a 2.9 or greater. 7 of them erupted in 2012. One of them was a 4.8 trembler that struck the town of Timpson in eastern Texas on May 17th. They all occurred close to the surface with an average on only 5 km.

Fortunately, my research hasn’t found that anyone was hurt. Though some homes have been damaged. Fort Worth Weekly recently told the story of the Rosalez family in Cleburne. One of the quakes popped a window out of its frame in their home and damaged their foundation. There are cracks in their walls now, some six inches long.

StateImpact Texas astutely points out that there’s also the question of earthquakes damaging injection wells and oil/gas pipelines. 13) As the ground shifts, will the structural integrity be compromised? This is particularly relevant, since Texas isn’t a state that’s known for earthquakes, so it’s unlikely they’ve been designed to withstand them.

As the shale gas boom continues so too will the need for injection wells. The U.S. is literally awash in cheap natural gas. Production was outpacing demand so greatly that some market observers started to question earlier this year if we’d run out of room to put all the gas. Nothing points to the drilling frenzy that grips our country better than this dilemma.

Never fear. The market is seeking to exploit fracking’s largess by coming up with new and better ways to use all the gas. Electric utilities are closing coal plants and opening new nat gas generators. LNG gas terminals are being built to export to markets all over the world. After getting burned in the 1990’s, some brave souls are even starting to pitch CNG vehicles again. Consequently, it’s likely that market forces will continue to demand more and more drilling. Given the huge revenues being produced, policymakers and bureaucrats will come under intense pressure to accept greater risks in return for what are perceived to be lucrative rewards.

But the question remains: What’s going to happen to the trillions of gallons of toxic water that we’re pumping into the ground beneath our feet? Each earthquake should serve as a reminder of this growing ocean sloshing around down there. For the Texas cattle ranchers and farmers who’ve been hard hit by some of the severest droughts on record, this must be a bitter irony.

References   [ + ]

4, 6.
8, 13.
10. ibid
11. United States Geological Survey

Author: Jesse Roche

An original thinker, Jesse enjoys writing, asking questions, and creating things. Greatly concerned with the deteriorating condition of public dialogue in the U.S., Jesse started in 2006. He posts essays there in his spare time about topics linked to major forces that are impacting society and require more analysis than they typically receive in the mass media. The modern monster is a focus of some of these essays and represents a developing body of thought about its place in American society and the role it serves. Jesse is currently working on a book.

Leave a Reply

Your email address will not be published. Required fields are marked *