Could a significant earthquake hit Chattanooga?
Energy from the quake 4,500 miles away near Alaska on Tuesday was detected in the scenic city.
Dr. Jonathan Mies spends a lot of time studying seismograms showing the strengths of earthquakes. Energy from the quake 4,500 miles away near Alaska on Tuesday was detected in the scenic city.
Mies says the odds of a significant earthquake here in the next 50 years are only about 2%, but it could happen if the ground moves at just one third the speed of gravity.
"Every second the ground will increase its velocity three meters per second in one direction, and quite possibly turn around and come back at that same speed," says Mies.
This could cause minimal damage like the 4.9 quake which hit northeast Alabama in 2003, or damage similar to or worse than the 5.8 magnitude earthquake in Virginia in 2011 which occurred in the Central Virginia Seismic Zone. There was a lot of broken glass, broken buildings, and cracks in the Washington Monument.
"We could have building collapse and that kind of thing with those sorts of ground accelerations. Our buildings are not particularly well designed or built to handle this kind of a hazard," adds Mies.
The 2011 quake prompted the U.S. Geological Survey to reassess the potential dangers of earthquakes in the eastern part of the country. However, Mies says it's impossible to predict how a strong an earthquake could be or when it would hit.
"The behavior of rock under these circumstances is just very, very difficult to predict. It just is," admits Mies.
While many small earthquakes occur each month in our seismic zone, the East Tennessee Seismic Zone, we don't notice most of them. Mies says it's hard to say whether these are signs of a stronger earthquake to come, but he's sure of one thing.
"They are plainly an expression of the seismic activity, the ground displacements that are occurring under our feet. They demonstrate that," says Mies.
He says there's no reason to panic, but we should be prepared.
"I would at least be familiar with what you should do in response, should we have an earthquake."
More Information | Earthquake Preparation and Response
More Information | Hamilton County Emergency Management Agency