Emergency managers from Bexar and surrounding counties gathered Thursday for a workshop to help them prepare for natural disasters; not for floods or tornadoes or hurricanes — but for earthquakes.

More than 40 officials met at the main office of the Alamo Area Council of Governments on Tesoro Drive.

They learned that small earthquakes quakes are very common in South Texas.

The workshop was organized by the Memphis, Tennessee-based Central U.S. Earthquake Consortium. They work to prevent injuries, deaths and the loss of property from earthquakes.

The consortium receives funding from the Federal Emergency Management Agency. Its associate director — Brian Blake — said natural fault lines and the disposal of oil fracking wastewater keep South Texas an active area for earthquakes. Representatives from FEMA and the Texas Division of Emergency Management were present at the workshop.

“In this area since 2017, there have been 33 earthquakes larger than a magnitude of I think a 2.5,” he said.

Blake said a 4.8 magnitude South Texas quake was recorded in 2011. The Texas-based Bureau of Economic Geology reports the Eagle Ford Shale area, southeast of San Antonio, is one of the most active earthquake regions of the state.

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Karnes County Emergency Management Coordinator Shelby Dupnik said they have felt 13 quakes this year, but some originated in nearby counties.

He said he attended the earthquake workshop just in case a bigger one comes one day. He noted the smaller ones do little to no damage, but create some chatter on social media.

“But you get on social media, people are, ‘Oh, well, my house shook, my dog ran away, my old mama’s wall cracked,’ but nobody says anything really other than that,” he explained.

The U.S. Geological Survey reports the injection of wastewater and salt water from fracking into subsurface disposal sites can trigger earthquakes.

Atascosa County Emergency Manager David Prasifka said mini quakes are also common in Atascosa County, and lines of saltwater trucks mean storage activity is brisk.

“We’ve got a lot of saltwater disposal sites. Things in the oil field have slowed down a little bit. They’re really hauling the saltwater trying to extract every bit of oil they can.”

The Texas State Historical Commission reports the largest earthquake to strike Texas was in August 1931 near the West Texas town of Valentine, registering a 6.0 on the Richter scale, and damaging buildings and adobe structures.

No deaths or injuries were reported in the town.

Brian Kirkpatrick can be reached at Brian@TPR.org and on Twitter at @TPRBrian.

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