Published on December 15th, 2017 | by Cynthia Shahan0
Is The Oil & Gas Industry Causing Texas Earthquakes? A “Landmark” Study Suggests Yes
December 15th, 2017 by Cynthia Shahan
There is more than what hits the eye, or in some places, shakes the house. A new report, Discriminating between natural versus induced seismicity from long-term deformation history of intraplate faults (PDF), explains. While we all make assumptions on hunches, it takes a scientist assisted by a group of scientists and geologists to assess whether seismic activity is induced by human activity or is of natural origin.
I know that the residents of Texas value the scope and beauty of their chosen state. And they should — the state offers magnificent skyscapes similar to Florida on the Gulf Coast. Austin, the Texas capital, is a mecca for the independent Texan wanting diversity, Willie, Austin City Limits, and eclectic music. Texas terrain ranges from coastal swamps and piney wood to rolling plains and hills — and desert and mountains. Let’s hope Texans care enough to consider what fracking might do to the state. Perhaps it’s time to revive the “Don’t mess with Texas” slogan created to cut down on littering.
The Washington Post reports on a strain from such practices in Texas. Ben Guarino’s article describes that an unnatural number of earthquakes hit Texas in the past decade. Continuing, he reports that the region’s seismic activity is increasing. “In 2008, two earthquakes stronger than magnitude 3 struck the state. Eight years later, 12 did.”
“Given the lack of faults in Texas’s most recent 300 million years of history, there is no known geologic process that could explain its sudden quake outbreak.” Maria Beatrice Magnani, who studies earthquakes at Southern Methodist University in Dallas, said that this has to be caused by humans. “There is no other explanation.” She was one of the researchers intent on getting to the bottom of the cause.
“Along with a team of researchers at the U.S. Geological Survey, Magnani, an author of a new report published in the journal Science Advances, attempted to better identify what has been causing the rash of Texas quakes.”
And what human activities popped up? Guarino points out the recent increase in natural gas extraction. The activity of fracking or hydraulic fracturing produces a lot of wastewater. “To get rid of it, the water is injected deep into the ground. When wastewater works its way into dormant faults, the thinking goes, the water’s pressure nudges the ancient cracks. Pent-up tectonic stress releases and the ground shakes.”
Magnani’s team of researchers attempted to make some sense of the rash of recent Texas quakes. “The main approach has been to correlate the location to where there has been human activity,” said Michael Blanpied, a USGS geophysicist and co-author of the new study.
The concerns about fracking have been forthcoming and the study is similar to what other earthquake experts had found — but with different analyses. From the abstract: “To our knowledge, this is the first study to discriminate natural and induced seismicity using classical structural geology analysis techniques.”
That sounds complicated, but the team notes that other researchers should see it as a solid approach. “We don’t expect a lot of pushback” from the scientific community, Blanpied said.
The Washington Post continues that the study authors’ unique approach sought out deformed faults below Texas. “This technique is called high-resolution seismic reflection imaging,” Magnani said. Using seismic reflection, the same tool that allows extractors to find oil and gas deposits in underground structures, they collected seismic data in response to an artificially generated wave that reflects back to the surface. “The result is ‘a little bit like an ultrasound,’ Magnani said, revealing not baby toes but twisted rock.”
Back to the abstract and graphics from the abstract (if you want to get further into the nitty gritty): “We analyze fault displacements on high-resolution seismic reflection profiles for two regions in the central United States (CUS): the Fort Worth Basin (FWB) of Texas and the northern Mississippi embayment (NME).”
Magnani and the group acknowledged what we’ve come to learn more and more regarding fracking ramifications: “On the basis of these observations, we must reject the hypothesis that these earthquake swarms are being triggered by tectonic forces. Rather, the data indicate that the FWB faults have experienced a remarkable lack of deformation in the past ~300 My, until the recent 2008 surge in seismicity, and independently confirm the interpretation by other authors of the recent seismic sequences in the FWB as induced rather than natural.”
The Washington Post points to supportive experts outside the study. “’This is a landmark contribution in the question of whether the Fort Worth basin earthquakes are man-made,’ said Cliff Frohlich, a geophysicist at the University of Texas at Austin who was not involved with the study. Frohlich said this research eliminates the possibility, sometimes raised by the oil and gas industry, that the Texas quakes are part of a natural cycle of faults that awaken every few thousand or million years.
“The seismic reflection data provide a powerful argument ‘that these earthquakes are something new and different,’ he said — activity stemming from the injection of wastewater deep into basement rock. (‘Most of the time it’s the large volume injection,’ he said, ‘not the little frack jobs.'”
Our sister site Planetsave reported a while back on the largest earthquake in Kansas — caused by fracking. What was the cause? Perhaps the video deserves another look.
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