Is hydraulic fracturing, also known as fracking, to blame for this cluster of earthquakes?
This is one of those stories that seems like something out of a science fiction novel but in fact it’s real life. Over a recent 24-hour period in and around Irving, Texas between Dallas and Fort Worth there were a bundle of earthquakes. And by bundle, I mean 11. The quakes ranged in magnitude from 1.7 to 3.6, according to EcoWatch.
The quakes were felt in metro Dallas where hundreds called 911 in fear. With more than 20 quakes since last September, it’s no coincidence that the area sits on top of a natural gas rich and heavily fracked shale deposit. Many researchers think hydraulic fracturing is to blame.
“The upsurge in quakes started in Texas around the time the oil and gas boom took hold several years ago,” reported StateImpact Texas. “The number of recorded earthquakes (most larger than 3.0) has increased tenfold since a drilling boom began several years ago. The Lone Star State is now one of the shakiest in the country, coming in sixth in the continuous U.S. for having larger quakes last year.”
In fact, the number of earthquakes in an area that rarely saw them before has increased by tenfold since the fracking boom began.
“It’s premature to speculate on the cause of this current series of seismic events,” said Brian Stump, Albritton Chair of Geological Sciences at Dallas’ Southern Methodist University (SMU), in a statement reported in the Dallas Morning News yesterday. “We’re just getting started. We want to support the local community in understanding these earthquakes, and the team appreciates the cooperation of the city of Irving, the United States Geological Survey (USGS) and IRIS [the U.S. Environmental Protection Agency’s Integrated Risk Information System] in helping us get the best information possible.”
According to StateImpact Texas, the earthquakes aren’t caused by the drilling used in hydraulic fracturing, they result from the disposal wells located thousands of feet under the ground. These wells store drilling fluid, a chemical-laced water encased in concrete.
“The model I use is called the air hockey table model,” Cliff Frohlich, a research scientist at the Institute for Geophysics at the University of Texas at Austin said to StateImpact Texas. “You have an air hockey table, suppose you tilt it, if there’s no air on, the puck will just sit there. Gravity wants it to move but it doesn’t because there friction [with the table surface].” But if you turn the air on for the air hockey table, the puck slips.
“Faults are the same,” he says. If you pump water in a fault, the fault can slip, causing an earthquake.
“Scientists in my community know that injection can sometimes cause earthquakes,” Frohlich says.
Related on EcoSalon:
Image: Simon Fraser University