IRVING (CBS 11 NEWS) – Officials in Irving continue their search for what may be triggering the recent swarm of earthquakes dogging Dallas’ neighbor to the west.
On Wednesday, an additional 15 seismograph monitoring stations were installed in Irving, with seven more to come in the next few days.
The big questions about the quakes — why and why now? Some say it may have to do with the land under the old Texas Stadium, where the Dallas Cowboys once played.
“They [earthquakes] can happen anywhere at any time,” explained Dr. Len Kubicek, a geology professor at nearby North Lake College. He says the old Texas Stadium site is directly over the Balcones Fault, which runs from Irving to San Antonio, paralleling Interstate-35.
Kubicek says natural forces are tugging on the fault from high in the Rocky Mountains and the Gulf of Mexico. “If you start pulling on this and stretching it, in this case you’re going to get two normal faults,” he said, using wooden blocks to demonstrate the action. “The Balcones Fault was actually one of these, that type of fault, and it’s due to stretching.”
But it hasn’t moved in 100-million years. So why now? One theory, according to Dr. Kubicek, was imploding Texas Stadium. He says it could have forced a release of stress energy.
“And if you beat on this and shake it, it’s going to have a tendency to slide. Not the big ones [faults], but all the little ones,” he said. “It can splinter into several faults and one of these little faults, especially where that stadium was, you do an explosion on top of it and beat it up and down — it has a tendency to move.”
Another theory is that wastewater injected thousands of feet underground during hydraulic fracturing could be a culprit. Kubicek said, “Imagine if the water gets into this fault, it will lubricate the sides and cause it to start moving, even though it didn’t want to move before.”
But there are no such wells anywhere in Irving and both Kubicek and state officials doubt they’re the source.
The unknown is worrisome to local residents. “It’s just a little unsettling, I would say,” Van Hays told CBS 11 News. He says his nearby homeowners association social network lit up the past two days, worrying about the cause.
Hays once lived in California and says Irving’s quakes are different. “The ones in California are more like the rumblers, that just rumbled. But this one was more like a sonic ‘boom.’ It’s just ‘boom!’ Just a real jolt.”
And that difference is one reason Dr. Kubicek is optimistic… California’s San Andreas Fault is much different and small quakes there could precede the big one. But small quakes here on the Balcones, he believes, may be just the fault relieving stress.
“If you get a lot of small earthquakes you’re probably not going to ever get a big one. Because if you have a big earthquake you have to have a lot of stored energy; and if you keep having little ones you can’t store it.”