Nerves were jangled and items were jolted off shelves by four earthquakes in North Texas yesterday, but no major damage was reported. All four quakes were centered in the same location in Irving, Dallas County, where there have been 20 quakes reported since October 2014, NBC reports. The four quakes—ranging in strength from magnitude 2.7 to 3.6—were centered near the old Texas Stadium site, former home of the Dallas Cowboys, and Southern Methodist University scientists are trying to determine the cause.
The United States Geological Survey says the quakes—two of which happened within seconds of each other starting at 8:11pm—were strong enough to break windows and be felt by many people in the area. Researchers say the quakes could be linked to stored stress in old fault lines, although the disposal of wastewater from the energy industry can also trigger small quakes. But "there are no oil and gas disposal wells in Dallas County," a seismologist with the Texas Railroad Commission tells the Dallas Morning News. "And I see no linkage between oil and gas activity and these recent earthquakes in Irving." (More Texas stories.)