Study Links Recent Texas Quakes to Oil Activity

A new study by researchers at the University of Texas at Austin concludes that human activity, particularly oil and gas production, has been a factor in earthquakes throughout the state for nearly 100 years.

The study’s conclusions are in a paper to be published Wednesday in the journal Seismological Research Letters. The Dallas Morning News reported the study concludes that man-made earthquakes in Texas began in 1925 and that activity associated with oil and gas production “almost certainly” or “probably” triggered 59 percent of the earthquakes detected across the state in 1975-2015, including recent seismic activity in North Texas.

Another 28 percent of the quakes were “possibly” triggered by oil and gas exploration and production, and just 13 percent were caused naturally.

“The public thinks these started in 2008, but nothing could be further from the truth,” Cliff Frohlich, senior research scientist at UT and the study’s lead author, told The News.

The study offers important new information that could affect future seismic threat assessments for Texas, said Robert Williams, a geophysicist at the U.S. Geological Survey in Golden, Colorado. The seismic activity has not occurred just in North Texas, but in the Permian Basin of West Texas and in the Texas Panhandle, he said.

“Those sites are new and may need to be considered by USGS in future induced seismic hazard maps,” Williams said.

Frolich and other researchers at UT and Southern Methodist University contend in the paper to be published Wednesday that state regulators have been reluctant to acknowledge any link between seismicity and industry. Indeed, such arguments have not impressed the Texas Railroad Commission, which regulates the oil and gas industry and is dismissing the new study’s conclusions.

“The commission will continue to use objective, credible scientific study as the basis for our regulatory and rulemaking functions. However, this new study acknowledges the basis for its conclusions are purely subjective in nature and in fact, admits its categorization of seismic events to be arbitrary,” commission spokeswoman Ramona Nye said in an email to the newspaper.

But Williams found the classification system in the Frohlich report convincing. “It is still based on correlation, and you’ll never know for absolute certain but it’s pretty strong evidence,” he told The News.

The study concluded that man-made earthquakes in Texas began in 1925 in the Goose Creek oil field near what is now Baytown, about 25 miles east of Houston. So much oil was extracted from the field that the ground sank, shaking houses and sending dishes crashing to the floor.

“As the industry has changed, the oilfield practices that caused earthquakes have changed as well,” Frohlich said.

According to the study, processes associated with hydraulic fracturing have triggered most of the earthquakes since 2008.