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The Rise in Texas Earthquakes Is 'Almost Certainly' Due to Oil and Gas Drilling

New research shows the number of tremors is linked to the state's oil and gas boom — and the authors criticize Texas regulators for being "slow to acknowledge" the role of industry.
Image via AP

Oil production is not only triggering earthquakes in Texas today, it was rattling the state as early as the 1920s.

Researchers at the University of Texas looked back at the history of the state's tremors and found a long list that were likely the result of the state's oil boom, even if the reasons varied over time. Most of the state's current seismic activity is probably or "almost certainly" the result of human activity, but man-made quakes occurred as early as 1925, the study found.


While Texas hasn't had the shakes as badly as neighboring Oklahoma, the number of noticeable earthquakes to hit the state has gone up from about two a year to about a dozen. The US Geological Survey recently added the Dallas-Fort Worth area to its seismic hazard map, warning that the risk of a damaging earthquake in a populated area has gone up significantly.

The above figure shows the location and cumulative number of natural (tectonic) and induced earthquakes in Texas between 1980 and 2010. (Image by Cliff Frohlich/University of Texas at Austin)

Scientists have linked the increase in seismicity to the disposal of the salty wastewater that comes up from oil wells, which is usually injected deep underground. And the boom in hydraulic fracturing operations, which allow drillers to reach previously-inaccesible pockets of oil, has meant a huge increase in the amount of that water being pumped deep below the surface.

In a statement accompanying the study, Cliff Frolich, associate director of the Institute of Geophysics at UT-Austin, said the findings should put to rest the debate over whether humans are causing quakes in Texas — but some of the early quakes were the result of activities far different than what's happening now. The earliest human-induced quakes occurred when drillers would rush to drain an oil field, leading to underground cave-ins that set off seismographs; between the 1940s and 1970s, oil companies pumped water underground to drive oil toward the surface, making it easier to pump. That contributed to quakes as well, he said.

The results were published this week in the scientific journal Seismological Research Letters. The authors were critical of Texas state regulators, whom they said were "slow to acknowledge" the connection between oil operations and drilling. The Texas Railroad Commission, which oversees the industry, called the study "arbitrary" and "subjective," according to Reuters, and said the agency had also taken steps to reduce injection volumes.

Regulators in Oklahoma and Kansas also have been trying to stop the shaking by telling oil companies to rein in the volume and depth of their injection operations. But Frolich said there's no easy solution to the problem.

"I think we were all looking for what I call the silver bullet, supposing we can find out what kinds of practices were causing the induced earthquakes, to advise companies or regulators," he said. "But that silver bullet isn't here."

Related: Damaging Earthquakes Are Now As Likely in Oklahoma City and Dallas As in Most of California

Follow Matt Smith on Twitter: @mattsmithatl