Professor says McMinnville not in danger of major quake
While Tuesday’s jarring 4.9 earthquake left people across seven states wondering what is next, experts in the Earth Science field say there is no need to panic given the geographic location of McMinnville between two earthquake threat zones.
“A 4.9 is pretty unusual for this neck of the woods,” said Dr. Hugh H. Mills, Professor of Earth Sciences at Tennessee Tech in Cookeville. “But a 4.9 won’t generally do much damage. It’s when we reach the 5.0, that’s the magic number, where it is considered threatening.”
Mills, who has performed research on earthquakes in this area, said the Tuesday-morning tremor epicentered near Ft. Payne, Ala., is an extension of the East Tennessee seismic zone.
“This is the biggest one recorded in this zone,” Mills said. “It really hasn’t been monitored for a lot of years, but we know this is the biggest one in recent history.”
Mills pointed out the quake was felt across seven states, ranging from Florida to Indiana. The reason for the widespread impact was the depth of the fault.
“In California, the faults are more shallow while here they tend to run deeper, meaning they are felt further away from the epicenter,” Mills said.
Mills noted the East Tennessee zone is considered the lesser of the two zones which encompass Tennessee, with the New Madrid fault getting most of the attention for good reason. The professor pointed out the New Madrid fault has been known for some of the most intense earthquakes to ever shake North America, with the 1811 and 1812 earthquakes.
While situated between the two zones, Mills said McMinnville and Cookeville are in fairly safe areas due to their distance from the zones.
“We really aren’t threatened by either one,” Mills said. “Now, a place like Memphis with its proximity to New Madrid, that may be a bit of a different story and I think they’ve taken some steps there as far as building codes.”
Mills said earthquakes are a reality, even though they are unusual here when compared to the West Coast.
“It’s not a matter of if they will happen, but when they will happen,” Mills said, admitting quakes are highly unpredictable.
Mills said the East Tennessee seismic zone is even more hard to read since little is known about it since such quakes tend to happen very deep in the ground in the region. Mills said experts are just now beginning to understand the New Madrid zone.
Mills added it is hard to say if the Tuesday quake could be a hint of something more severe to come in the near future.
“They are random so it’s hard to say what’s going on down there,” Mills said.
“But, they are so rare in this area, it’s hard to justify making tougher building codes for earthquakes since they haven’t been a big threat. It’s good to have emergency service preparedness, but fortunately for this area, we are pretty well away from the main zones of activity that we know about.”