A series of five earthquakes shook the state of Tennessee near the North Carolina border within a span of five hours.
The earthquakes hit the Eastern Tennessee Seismic Zone, one of the most active areas in the southeastern U.S.
The Southern Appalachian Seismic Zone, a seismic region stretching from northwestern Georgia, through Tennessee and into northeastern Alabama, was hit by a swarm of 5 earthquakes on February 11, 2020. The same area was struck by the seventh strongest quake in East Tennessee in more than a century on January 20, 2020.
The five tremors occurred within 5 hours. Four of them were clustered around Greenback and one hit near Sweetwater. They were all under M2.0:
- M1.7 @ 2:48 a.m. EST, 3 miles east of Greenback
- M1.4 @ 3:23 a.m. EST, 1.2 miles northeast of Greenback
- M1.6 @ 4:11 a.m. EST, 1.9 miles northeast of Greenback
- M1.3 @ 6:06 a.m., 1.9 miles east of Greenback
- M1.6 @ 6:56 a.m. EST, 5 miles east of Sweetwater
Meanwhile, another M2.7 earthquake hit near Fincastle at 11:33 a.m. EST on February 12, 2020, which was reported by at least 40 people on the USGS homepage.
Eastern Tennessee Seismic Zone (ETSZ)
The Eastern Tennessee Seismic Zone (ETSZ) is one of the most active areas in the southeastern U.S. Its known faults are generally ancient and no known active faults reach the surface.
The largest earthquakes in the ETSZ are the M4.6 in 1973 near Knoxville, Tennessee and the M4.6 on April 29, 2003 near Fort Payne, Alabama.
However, the USGS has estimated that earthquakes as large as M7.5 are possible in the Southern Appalachian Seismic Zone.