Tennessee Hit By Five Earthquakes in Less Than Five Hours

Tennessee was hit by a string of earthquakes in the early hours of Tuesday morning at locations close to the North Carolina border—experiencing five quakes within the space of five hours.

Four of the five quakes were clustered around Greenback, a city approximately 30 miles southeast of Knoxville, Tennessee, with a population of around 1,100. One was near Sweetwater, a city of just over 5,500 people that is known for its vast underground lake, the Lost Sea.

According to data collected by the United States Geological Survey (USGS), the first to strike was the largest—measuring magnitude 1.7. The earthquake struck at 2:48 a.m. EST, radiating from its epicenter 3 miles east of Greenback.

The second occurred half an hour later, 1.2 miles northeast of Greenback. A magnitude 1.4 earthquake occurred at 3:23 a.m. EST, and was followed a little under an hour later by a 1.6 magnitude quake at 4:11 a.m. EST, 1.9 miles northeast of Greenback.

The final two took place in quick succession—the first, a magnitude 1.3 earthquake 1.9 miles east of Greenback at 6:06 a.m. EST and the second, a magnitude 1.6 earthquake 5 miles east of Sweetwater at 6:56 a.m. EST.

All five were under magnitude 2.0. Any earthquakes under this are unlikely to be felt by people.

The earthquakes took place on a strip of land called the Eastern Tennessee Seismic Zone (ETSZ), also known as the Southern Appalachian Seismic Zone, which stretches from northwestern Georgia, through Tennessee and into northeastern Alabama.

According to USGS, it is one of the most active areas in the southeastern U.S. but earthquakes here tend to be small and rarely damaging. Most are too small to be felt by anything other than a seismograph—as was the case with the five that took place yesterday.

Those that do take place at the tend to be felt over a larger expanse than earthquakes that occur in western states like California, with a magnitude 4.0 magnitude in the ETSZ often being felt as far as 60 miles from where it hit.

One of the largest to strike the region was a magnitude 4.6 earthquake, which hit Fort Payne, Alabama, on April 29, 2003.