Energy and Environment Reporting for Texas

Mapped: The Latest Earthquake Swarm in Texas (Update)

View North Texas Earthquakes in a larger map

A map of recent earthquakes (in red) and oil and gas wastewater disposal wells outside of Fort Worth. Active disposal wells are in green; inactive wells are in yellow. Map by Michael Marks/Terrence Henry

Ten  Seventeen* earthquakes in just a month, the biggest a magnitude 3.6. That’s what small towns like Azle and Springtown Northwest of Fort Worth have had to deal with recently. (*More quakes have struck Azle since this story was originally published: on November 21, 23, 25, 26 and 29. The Nov. 25 quake measured 3.3.)

The region is also home to several disposal wells, which are used to store massive amounts of wastewater from oil and gas drilling. In other parts of the Barnett Shale drilling area disposal wells have been linked to similar series of quakes. You can see where the quakes have occurred recently around the town of Azle, as well as active and inactive disposal wells in the region, in the map above. The quakes are in Tarrant and Parker counties.

Cliff Frohlich, Associate Director of the Institute for Geophysics University of Texas at Austin, has lead research into links between oil and gas drilling activity and manmade earthquakes. His study of earthquakes in the Barnett Shale found that disposal wells were responsible.

The current string of quakes hasn’t been known to have caused any serious damage yet, but it has rattled residents. “It shook the ground, and it sounded like a boom,” one resident of Azle tells the Fort Worth Star-Telegram. “I honestly thought it was an explosion, and I thought it might have something to do with the gas wells behind our home.”

Earthquakes measuring 4.0 or higher are more generally known to cause damage. At level 5.0 or higher, quakes can damage old or poorly-designed buildings. But the level of damage can depend on the location of the quake. “An earthquake in a densely populated area which results in many deaths and considerable damage may have the same magnitude as a shock in a remote area that does nothing more than frighten the wildlife,” the US Geological Survey notes on their webpage.

You can read more about the link between oil and gas wastewater disposal wells and manmade earthquakes at our topic page on the subject.


  • Kim Triolo Feil

    ANGA can spin and $pend all it wants, but they’ll never have enough money to stop the frenzy of the social media sharing all the anti drilling info wich abundant personal tesamony (see The Harmed List) and scientific reports. Look at all the bloggers out there now! The risks this industry has to regular folks’ health and property values along with attention grabbing earthquakes is while the royalty checks have been looking like beans. Plus there are enough 100 year storms that are coming at a break neck pace that continue to rack up the dollar lo$$es. Finally consider the drought on the fracker’s much needed water supply for their unproven safe unconventional technology. All this together will be too much for the frackers to keep this up and make a profit. On a humorous note, there is an upcoming Houston conference to teach the frackers how to best “Viagra Up” (lift compression and stuff) their petering production in the Eagleford Shale….In the end it was money that fracked us into this and it will be the frackers loss of money that will end this insanity. We need an OC to MSB civil war…..Ordinary Citizen Movement to Salvage our Biosphere-we have no planet B.

  • richardguldi

    When the ground become Swiss cheese, this is what happens. What is the danger that ground shifting will be enough to release toxic fracking compounds into an aquifer? That would be the death knell for a large region of Texas.

  • It would be compelling to compare this trend of tremors in areas of water disposal well to other regions where hydraulic fracturing of shale is prevalent.

  • curaecivem

    Its interesting to me that in the last 1990s the Attorneys General of 46 U.S. states ganged up on Big Tobacco and sued them due to the alleged medical costs in their respective states they claimed were linked to smoking, (See Tobacco Master Settlement Agreement, which resulted in Big Tobacco agreeing to pay $206 billion over the first twenty-five years of the agreement,) but few AGs will likely go after Big Oil for even more egregious health risks linked to fracking. not to mention the risks to their respective state environments and citizens’ health. To me, this blatant hypocrisy is very telling of who really rules the purse strings when it comes to U.S. Environmental policy.

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