Seismologists are installing more measuring equipment in a Dallas suburb as earthquakes continue to rattle North Texas.
Southern Methodist University researchers said Friday that the equipment will help pinpoint the origin of the quakes.
The Dallas Morning News reports that Irving has experienced about 50 small tremors since 2008, with a series since October that included a 3.3.-magnitude temblor near the former home of the Dallas Cowboys.
Small earthquakes have become more common recently in Texas and Oklahoma.
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.
Elsewhere in North Texas, researchers are examining whether swarms of earthquakes near Azle are linked to fracking wastewater disposal wells.