SMU researchers say Dallas should prepare for larger earthquakes

The 3.1 magnitude earthquake that hit Dallas Friday morning showed that this sequence of tremors is not dying down as quickly as many had hoped.

“Past sequences have popped up and decayed,” said SMU seismologist Brian Stump. “This most recent event reminds me that we need to continue to monitor this sequence to see if it actually does decay.”

Previous clusters that have shaken the Dallas-Fort Worth area include the 2008-2009 cluster near DFW airport; the 2009-2010 cluster in Cleburne; and the 2013-2014 events in the Reno-Azle area. The sequences have culminated in quakes ranging in magnitude from 2.8 to 3.6.

Friday’s earthquake, the latest in a series that began in April 2014, was smaller than the strongest tremor to shake Dallas and Irving so far: a 3.6 magnitude temblor that hit on Tuesday, January 6.

“Every earthquake sequence can be a little bit different,” said Stump.

He added, “We do need to keep in mind there could be larger earthquakes and think about how we might prepare for that.”

Stump and his colleagues are looking into the question of how large an earthquake this sequence could produce by mapping the fault that is causing the tremors. The larger the fault, the farther it can slip, and the more strongly it can shake the ground.

As I reported on Sunday, researchers around the country are investigating ways of reducing the risk of damaging quakes related to oil and gas activity. The approaches include mapping dangerous faults and avoiding them during fluid injection, and “fingerprinting” tremors.

In North Texas, scientists have linked the DFW and Cleburne clusters with wastewater injection wells, where companies dispose of fluids used in hydraulic fracturing and other industrial processes. Findings on what caused the Azle and Dallas-Irving quakes are still pending.

Did You Feel It? Anyone who experiences an earthquake should report it on this USGS Web site. Researchers like Susan Hough, whose work I discussed in this story, use public reports to study how strongly earthquakes shake the ground and to refine their understanding of how natural quakes differ from human-induced ones. Scoop