10:36 am
Wed August 24, 2011

Earthquake Above 4.5 Unlikely in Central Texas

After yesterday’s panic on the East Coast over a 5.8 earthquake, we wondered what the odds were of a similarly sized tremor hitting us.

Turns out, the odds are pretty slim. University of Texas seismologist Cliff Frohlich has studied earthquakes for 39 years. He says West Texas had earthquakes in 1931 and 1995 that were near a magnitude 6.0. The 1995 quake was even felt by some people in Austin.  Central Texas had its own 4.0 earthquake in 1902.

But anything more severe than that is unlikely, because Austin is not located near the boundaries of tectonic plates.  However, about ten percent of earthquakes occur in the interiors of tectonic plates, so a higher magnitude tremor is not entirely outside the realm of possibility.  

“One of the tough things about this business is that it’s hard to say never,” Dr. Frohlich said. “When the Japan earthquake happened this year, the magnitude 9, I and most of my colleagues would have said you couldn’t have had an earthquake bigger than 8.3 there. And we had a 9.”

“I don’t think you could have an earthquake bigger than 4.0 or 4.5 in Central Texas, but I could be wrong,” he said.

Check out this larger image of the tectonic map of Texas pictured above.