2 moderate earthquakes hit southwest of Mansfield in Johnson County

The U.S. Geological Survey recorded two moderate earthquakes in Johnson County Wednesday afternoon.

A 3.0 and a 3.2 magnitude quake hit about 5 miles southwest of mansfield just after 1 p.m. Earthquakes that size typically cause little to no significant damage, according to Justin Rubenstein, research geophysicist and project leader of the USGS Induced Seismicity Project.

“We wouldn’t expect any damage or anything like that,” Rubinstein said. “People that are going to be very close to the epicenter might be a little bit alarmed but nothing more than that.”

Johnson County Emergency Management Coordinator Jamie Moore confirmed no damage reported in the county as of Wednesday afternoon.

“The majority of what was reported were shaking pictures on the walls, rumbling and things of that nature,” he said. “It’s just a very unusual feeling and obviously gets a lot of attention.”

While it’s too early to know the exact cause of Wednesday’s earthquakes, most earthquakes in North Texas are induced or caused by human activity, according to Rubinstein. That includes via wastewater disposal or the underground injection of waste byproducts from oil and gas production in the area.

Rubinstein said a final determination is awaiting industrial data.

Many hydraulic fracturing operations, or fracking, use injection wells to dispose of contaminated fluids. The concrete-encased wells can reach thousands of feet underground and store waste liquid from multiple fracking operations.

North Texas hasn’t seen many earthquakes above a 4.0 magnitude, but places with more drilling like the Permian Basin have experienced earthquakes above a 5.0 magnitude. After a recent earthquake in the Permian, the Texas Railroad Commission — which regulates the state's oil and gas industry — suspended injection permits in the region.

The two major oil formations in North Texas are the Bend Arch–Fort Worth Basin and the Barnett Shale. Rubinstein said the greater dallas area has seen an uptick in earthquake activity since about 2008 — and most of them are induced.

“There’s been clusters of earthquakes since then, near DFW airport, near Venus, near Irving, near Azle,” he said. “There's been smatterings of earthquakes in a number of different locations in this broader Fort Worth basin, the Barnett Shale.”

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