Could a big earthquake strike the Tennessee Valley?
A recent quake in the Tennessee Valley registered only as a 2.8 on the Richter scale, but are we underestimating the frequency or potential strengths of quakes in our area?
"It's very disconcerting when the ground starts moving. And very impressive," says Dr. Jonathan Mies, a geology professor at the University of Tennessee at Chattanooga. The quake he recalls happened while on a trip to Costa Rica a few years ago. A native of the Chattanooga area, he says that 6.4 is no comparison to the tremor which struck our region Tuesday evening.
The Scenic City falls in the East Tennessee Seismic Zone, stretching from northeast Alabama to western Virginia. It's characterized by frequent, small quakes that are rarely felt. But some in recent decades have been destructive.
"One down near Ft. Payne and one west of Knoxville," says Mies.
They occurred in the 2000s and 1970s, respectively, and each measured 4.6.
But prehistoric indications of much stronger quakes has been found in rock formations in the Tennessee Valley. These markings are called paleoseismites.
"They find paleoseismites to indicate that this seismic zone has produced large earthquakes, but before any sort of historical record," explains Mies.
Based on the distant and recent pasts, Mies believes history could repeat itself.
"On the time frame that a geologist considers, you would have to consider it's capable of producing another large earthquake," fears Mies.
Something that concerns Chattanooga residents Amanda Krumnow and Patrick Jackson.
"We always hear about things on TV that can happen. We're definitely concerned about our area," says Jackson.
"Most people don't have a game plan. I don't have a game plan. What happens if there's an earthquake?" questions Krumnow.
A legitimate concern since it's impossible to know when it may strike.
"It could happen soon or it could happen 100 years from now. 1000 years from now," adds Mies.
Mies also says that a dense network of additional seismometers has been used around the country the past few years. Right now some of them are in the Tennessee Valley. The hope is to gather more and more data on activity deep in the earth's crust where most quakes in our area originate, as opposed to along a fault line. This may lead to the eventual possibility of predicting big quakes.