By Bridget Lewis
An earthquake shook the Irving area around 3:21 a.m. on Sept. 11. Many residents slept through the magnitude 2.9 earthquake.
The earthquake’s epicenter, or origin point, is recorded at 32 degrees 50 minutes north and 96 degrees 57 minutes west. Residents will know this place as the North O’Connor Boulevard and West Rochelle Road intersection.
Some students reported that they did not even feel the earthquake and were unaware of it until the following morning. Those that did wake up during the earthquake reported hearing a rumbling sound and feeling the ground shake.
“I woke up when I felt the ground shake and thought it was an earthquake,” said senior Sarah Sokora. “I’ve never been in one before, but I knew they happened here.”
Other students reported hearing a jolt or rumble and feeling the ground shake as well. There are no reports of any property damage or any injuries resulting from the earthquake on or off campus.
This earthquake is one of several that occurred in the past week. Arlington was hit by magnitude-2.4 and -2.5 quakes on Sept. 7 and Sept. 12, respectively.
Due to hydraulic fracking activity in the Irving area, some have suggested that human activities induced the seismicity in the area. Fracking has been known to cause man-made earthquakes.
Fracking is a drilling process that pumps millions of gallons of water and chemicals at high pressures under the earth’s surface. Fracking by itself is not linked to earthquakes. The disposal of the wastewater from fracking, however, has been linked to them. The wastewater of fracking is disposed of by pumping it into underground disposal wells thousands of feet deep. These fluids decrease the friction in faults, causing them to shift and resulting in earthquakes.
Though the fault line running through Irving is inactive, the disposal wells can cause the faults to shift slightly. It is uncertain whether that was the cause of Thursday’s earthquake.
Cliff Frohlich, senior research scientist at the Institute for Geophysics at the University of Texas at Austin, published a 2012 study on the correlation between injection wells and small earthquakes in the Barnett Shale region of North Texas. The Barnett Shale is a geological formation beneath Dallas and Fort Worth that holds large amounts of natural gas. Before the development of fracking, these natural gases were difficult to reach.
“[Frohlich] found that the most reliably located earthquakes — those that are accurate to within about 0.9 miles (1.5 kilometers) — occurred in eight groups, all within 2 miles (3.2 kilometers) of one or more injection wells,” a U.T. Austen press release stated. “Before this study, the National Earthquake Information Center had only identified two earthquake groups in the area strongly associated with specific injection wells. This suggests injection-triggered earthquakes are far more common than is generally recognized.”
Artificially-induced earthquakes are on the rise, according to the U.S. Geological Survey. Although wastewater disposal appears to have caused some major earthquakes in the past, such as the magnitude 5.3 earthquake in Raton Basin, Colo. in 2011, it has not yet been linked to quakes above magnitude-6. There are about 50,000 permitted oil and gas injection and disposal wells across Texas, according to the Railroad Commission of Texas.