Energy and Environment Reporting for Texas

What’s With All These Earthquakes in Texas?

StateImpact Texas

A hydraulic fracking operation in the Barnett Shale.

Call it a new Texas tradition: An earthquake hits and the ground has barely stopped shaking before people start looking for oil and gas drilling operations near the quake zone.

This past week saw a big jump in rare seismic activity across the state. Last Thursday, a 4.6 magnitude earthquake startled San Antonio residents early in the morning. And this Sunday, a 2.1 magnitude quake shook Keene, a small town just 25 miles south of Fort Worth. Then, early this morning, the U.S. Geological Survey says a 2.6 magnitude quake hit near Fort Worth.

All those places are relatively close to drilling operations and disposal wells.

Zac Trahan, the Program Director for the Dallas-Fort Worth office of Texas Campaign for the Environment (TEC), pointed a finger in that  familiar direction. He believes that the disposal wells for hydraulic fracturing operations may be behind the increase in earthquakes outside of Dallas-Fort Worth.

“North Texas historically has not had a lot of earthquakes and seismic activity,” Trahan said in an interview with StateImpact Texas.

But as the region has experienced a boom in natural gas drilling and an accompanying increase in the disposal wells used to store drilling by-product, “we’ve seen earthquakes increasing in this region in the past few years,” Trahan said.

The numbers back that up. In recent years, the Dallas-Fort Worth area has expanded hydro-fracking operations in the Barnett Shale. Since 2010, the area has witnessed at least ten minor earthquakes.

But the two earthquakes this past weekend also illustrate the difficulties in determining a cause-and-effect relationship between disposal wells and quakes.

“The situation south of San Antonio is more complicated than the one south of Dallas,” said Dr. Cliff Frohlich, the Associate Director of the Institute for Geophysics at the University of Texas at Austin.

The reason? Oil and gas operations, spurred by fracking technology, only recently began around the Dallas area. Frolich said that makes a correlation between quakes and fossil fuel development easier to spot.

On the other hand San Antonio has been developing the Eagle Ford since the 1950s, and there’s been earthquakes in that area since the 1970s.

“Now, they are doing additional hydraulic fracturing and disposal and there’s earthquakes. So, it’s hard to say whether these are related to the same old, same old business or something new,” said Frohlich.

And, for Frohlich, this past week’s seismic fits might not be related to hydro-fracking disposal wells at all.

“You can’t draw a perfect link. One thing, it’s very difficult to know exactly where the earthquake occurred. When the U.S. Geological Survey reports an earthquake it can be mislocated by five miles or even more. So, we really don’t know where the earthquake was with respect to wells,” said Frohlich.

Nevertheless, there is growing evidence linking quakes to drilling disposal wells.

A recent study requested by the Department of Energy (DOE) and conducted by the National Research Council (NRC) indicates that long-term disposal wells can be linked to increased seismic activity.

In fact, the debate appears to have moved from whether drilling operations cause earthquakes to how dangerous those earthquakes might be.

The NRC study suggests that wastewater disposal wells used in the hydro-fracking process don’t pose as great of a risk of causing earthquakes as traditional disposal wells. Unlike other disposal processes, hydro-fracking wastewater disposal often occurs at low pressure, reducing the likelihood of affecting nearby faults to create an earthquake.

And even if wastewater disposal does induce earthquakes, Dr. Frohlich maintains that we haven’t seen anything too alarming.

“The earthquake Sunday was around a 3.6 [outside of San Antonio]. That’s still a pretty small earthquake. A 3.6 shakes things, maybe chandeliers swing and something falls off your shelf if you’re really close,” said Frohlich.

But a ProPublica report published Monday, indicates that operators don’t always follow proper protocol when injecting wastewater. They inject the water back into the earth at pressures beyond suitable levels, the report found.  This can agitate fault lines just enough to generate noticeable earthquakes. The report also shows how toxic liquid can leak out of disposal wells.

All of this information will likely be the subject of debate before the House Committee on Energy Resources today. The Committee is meeting to discuss state regulations governing oil and gas well construction and pipeline safety, as well as the process by which oil and gas operators submit well logs.  You can watch that hearing by clicking here.

Sheyda Aboii is an intern with StateImpact Texas.


  • Mom

    Sad but yes we are destroying the Earth and leaving nothing for our children.

    • Had enough polluter greed

      To everything there is a season, and there is a time to stand up against those who destroy the earth.  Now is that time.

  • Shihtzulover5

    Harold Hamm the Oklahoma based founder and CEO of Continental Resources the 14th. largest oil company in America was named Mitt Romney’s top energy advisor in March. Just a few weeks later he donated 985,00 to a pro-Romney super Pac. He will start drilling the Bakken Shale of North Dakota which will yield 24 billion barrels of oil. Can you imagine what that will do to that state?

    • Jovina

      They will pipe the oil through our US Heartland and export it out of Texas to the highest bidding country, because other countries are willing to pay more our our oil and gas than Americans are. WWJD?

  • Matt030704

    Ughh. More fracking excuses. It’s one of two things. Government detonations of underground tunnels to build an underworld. Or mother nature is finally stepping up and showing who’s boss. I live in VA. Just north of mineral where the 5.8 struck last summer. Too many new locations have received earthquakes in the last year for the fracking operations which have been going on for decades to suddenly create problems. After we put our heads together and stop listening to the media is when people may realize that’s something serious is happening. For all these fracking believers are just being lied too. Just a simple way for the government to coverup the real truth. Whether is man made or gods plan. The government isn’t being honest as to the real causes.

    • ozonator

      A good excuse to deny Obamacare as well for aging Babyboomers – “been going on for decades to suddenly create problems” and buy more NRA guns and drugs.

    • Pamela Christian

      I believe they are speculating just like all the scientists, about how old the earth is. And etc. They really have no idea. But people will believe. The Bible talks alot about the earth and the end times. 1-888-NeedHim.

  • Jovina

    We are in our third year of rationing water so the oil industry can frack our land by polluting millions of gallons of water. Even when the drinking water is catching on fire out of the home faucets, they continue to deny the fracking cause and effect. Then, they export the oil to the highest bidding country. America the beautiful, and justice for all. Allegiance to Texas and corporate money. Will more corporations want to move to Texas? Boeing chose Chicago.

    • Geek0id

      “Even when the drinking water is catching on fire out of the home faucets”
      Stop right there. That is an effect from methane in ground water and has been noted for well over 100 years.
      You would need to explain several process that would need to happen for fracking to cause that.

  • ozonator

    They can’t spell “fool” without “U”.  “ExxonMobil CEO Rex Tillerson … blamed a public that is “illiterate” in science and math” (“Exxon’s CEO: Climate, energy fears overblown”; JONATHAN FAHEY, Associated Press; huffingtonpost.com, 6/27/12). For example, never able to do science and showing no problems to writing well enough to write grants for free cash from the EssoKochs, “WUWT Status report … Posted on June 26, 2012 by Anthony Watts … Some of you … may also have noticed a number of spelling and grammatical errors in recent WUWT blog postings. This is due to the fact that after over five years of blog posting, I have succumbed to a problem that plagues many people who use the computer too often -carpal tunnel syndrome. … has gotten severe enough to interfere with my ability to use the keyboard and mouse” (Tony ‘who lacked a mothers’ love because she preferred a pack of cleaner cigarettes’ Watts; whistlesuckers perfuming the stink at wattsupwiththat.com). 

  • Iidentifyhypocrites

    Of course, abortion is killing well over 500,000 children per year in the United States, way more than earthquakes, whether or not caused by fracking, will ever kill.  Those Kool-Aid drinkers who claim to be worried about “our children’s future” and “Mother Earth” ought to focus on a true disaster.

    • Geek0id

      By definition no child dies from abortion. Please stop using scare words to make it seem like you have an argument you don’t really have.

  • Angela

    There have been over a hundred earthquakes in Texas since 1847. Ps: there was no fracking in Texas in 1847. Just saying. Today’s society always pointing the finger to blame someone… smh.

  • Geek0id

    Don’t say ‘more’ and ‘increased’ without linking to trend data over at least 20 years.
    Otherwise the whole argument is specious, at best.
    It’s really temping to see an event, the other and assume they are related. IT’s human nature, but very wrong and flawed.
    Before some tried to pound their meat hooks into their keyboard in an attempt at some rant, please note I give no opinion on fracking.

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