Add one more study to the pile of evidence that activity related to oil and gas drilling is responsible for an unusual spate of earthquakes rattling Texas. This week, University of Texas scientists published a report in the Journal of Geophysical Research: Solid Earth that said it was plausible that a 4.8 shake in the East Texas town of Timpson in 2012 was caused by the injection of wastewater from fracking into the ground.
Plausible was as far as the researchers were willing to go, however, and that's unlikely to sway the oil-industry loving Texas Railroad Commission that drilling and earthquakes are related.
North Texas had virtually no earthquakes before fracking began in the region and it's had hundreds since. People in Irving are calling their insurance agents about getting earthquake coverage, and DFW school kids are doing duck and cover drills like it's 1983. The railroad commission has had to hire a seismologist. The U.S. Geological Survey's newly released earthquake risk map says North Texas has a 1-5 percent chance of being significantly affected by an earthquake in 2016. Before fracking came to the region, that risk was effectively zero.
Still, even a really convincing post hoc argument is still a post hoc argument. Craig Pearson, the railroad commission seismologist, has consistently denied links between fracking and the quakes. When XTO Energy and Enervest were brought before the railroad commission to show that they weren't responsible for the earthquake swarm that hit near Azle and Reno in 2013, the commission ruled with the frackers, despite an SMU study that said that human activity likely led to the swarm of tremors. The SMU study relied on the timing and proximity of wastewater injection activity to tie the fracking byproduct to earthquakes, but it wasn't a smoking gun.
The new UT study, released Wednesday, used a sophisticated computer model to map the potential effects wastewater would've had on the fault that caused the Timpson quake. Likely disposal scenarios were tested to see whether or not they would have been enough to cause the faults in Earth's crust that run underneath Timpson to slip and cause an earthquake.
"It is part of a continuing research effort by The University of Texas at Austin," Peter Eichhubl, a senior research scientist at UT said in a statement announcing the findings. "We used a more rigorous approach than previous studies, but our analyses are limited by the availability of robust, high-quality data sets that describe the conditions at depth at which water is injected and earthquakes occur. This study demonstrates the need for more and higher quality subsurface data to properly evaluate the hazards associated with wastewater injection in Texas."
The data Eichhubl and the SMU researchers behind the Azle study need aren't available yet, but could be on the way. The Texas Legislature allotted $4.5 million to the TexNet monitoring project during the last session that will place seismic monitors throughout the state to provide robust data when quakes rumble.