Seismologists Expand Texas Earthquake Study

Southern Methodist University seismologists will install more measuring equipment Monday in a Dallas suburb as earthquakes rattle North Texas.

More localized seismometers in Irving are “the first step in understanding the nature of the seismic activity,” professor Brian Stump said in an email Friday.

While earthquakes in Irving are not unprecedented – the city has experienced about 50 small tremors since 2008 – about a third have occurred just since October, according to the Dallas Morning News. That includes a 3.3-magnitude temblor near Texas Stadium, the former home of the Dallas Cowboys.

Small earthquakes have become more common recently in Texas and Oklahoma.

“The issue most people are concerned about is the increasing frequency of the quakes,” Irving City Manager Chris Hillman told the newspaper.

In October, state officials amended rules for disposal well operators amid concerns that high-pressure injections can trigger earthquakes.

About 40 miles from Irving, SMU seismologists are examining whether swarms of earthquakes near the city of Azle are linked to disposal wells, where thousands of gallons of water used in hydraulic fracturing are injected every day.

In neighboring Reno, disposal well operators must prove the injections will not cause earthquakes before receiving city permits.

Texas hired its first seismologist to investigate any link between quakes and fracking after a group of residents from Reno and Azle traveled to Austin to ask the Railroad Commission, the state’s oil and gas regulator, to halt the drilling.

Geologists say earthquakes of magnitude 2.5 to 3.0 are generally the smallest that are felt by humans and that damage is not likely from earthquakes that measure less than 4.0.