June 27, 2019 602 PM
SOUTH PRESIDIO COUNTY – When a 3.9 magnitude earthquake struck in Big Bend Ranch State Park (BBRSP), a mother and daughter were the only two to reportedly experience it.
The tremors shook south Presidio County just before 9pm last Monday, June 17, rattling the park headquarters, and not much else.
The BBRSP had no visitors present that night, because of the high summer temperatures, and the park’s remote location. Only a staffer and her daughter, living on site at the park’s Sauceda Headquarters, felt the quake “like a little thunder,” according to the park’s Office Manager, Sylvia Aguilar. The woman and child were 5.3 miles from the epicenter.
Aguilar heard about the event from the unnamed staffer after the fact. She relayed that the woman heard a thundering sound, and the daughter, who was watching television at the time, “saw the TV move a bit.” Park rangers located at Botella Junction, 11.5 miles from the epicenter, didn’t report feeling anything.
The seismic activity that evening clocked in as a “minor” class earthquake, which is not expected to cause damage, just slight movement. The epicenter of the event happened along the Main Road, near the Agua Adentro Pens and Papalotito Colorado Campsite, and Aguilar said she, “didn’t see any rocks had fallen or see anything,” near those sites after the event.
Remarkably, at 3:11pm two days later on June 19, a second, smaller 2.5 magnitude earthquake was recorded just north of the park’s boundaries, four miles northeast of the first quake’s epicenter, according to the United States Geological Survey (USGS.)
Don Blakeman, a Geophysicist at the National Earthquake Information Center, and part of the USGS, said these types of intraplate quakes are common across the United States. Most earthquakes in the world occur at the borders of two tectonic plates as they make contact, but West Texas is located in the middle of a plate, so its “intraplate” tremors are just the plate itself relieving stress.
The USGS is not in the business of forecasting earthquakes, according to Blakeman. The two quakes are likely related, but don’t necessarily indicate anything bigger ahead. “Any kind of earthquake is a stress relief. There’s nothing to be alarmed here, this is a kind of common thing.”