The fault that produced North Texas' largest quake could produce an even bigger one, study says

The fault that produced North Texas' largest quake could produce an even bigger one, study says.

By Anna Kuchment
Staff Writer

The town that experienced a 4-magnitude earthquake in May 2015 — the strongest quake ever recorded in North Texas  — sits on a fault with the potential to produce an event 10 times larger,  suggests a new study led by scientists at Southern Methodist University.

The report also concluded there was “substantial evidence” that the quake, near the Johnson County town of Venus, was triggered by the underground disposal of wastewater from oil and gas operations.  

The study was the latest to investigate North Texas’ earthquake surge, which began in 2008 and has generated more than 200 tremors. The most recent widely felt event was a 3.1-magnitude quake that struck near the border of Irving and Dallas on Aug. 25.

The U.S. Geological Survey, backed by peer-reviewed studies, has categorized the post-2008 earthquakes as human-induced. But the Railroad Commission of Texas, an agency that both regulates and promotes the oil and gas industry, has not accepted the USGS findings.

In response to the new study, published Sept. 4 in the Journal of Geophysical Research, the Railroad Commission said through a spokesperson only that its seismologist, Aaron Velasco, had not had the chance to thoroughly review the paper.  

The team of seismologists identified two previously unpublished faults near Venus and Mansfield, about 30 miles southwest of Dallas. The researchers found that the fault responsible for the 2015 quake is at least 4 miles long and holds the potential to produce a 5-magnitude or greater earthquake if the fault ruptured along its full length.

“This is not meant to be taken as, ‘a magnitude 5 will happen on this fault,'” said SMU’s Heather DeShon, who led the new study. Until now, the fault has ruptured only in smaller sections, and it may never produce a bigger event, she said. 

Read the full story.