The ETSZ is one of the most active earthquake zones in the eastern United States.
A few damaging earthquakes have occurred in the ETSZ; the largest historic earthquakes measured 5.1 magnitude, occurring in April 29, 2003 near Fort Payne, Alabama and August 9, 2020 near Sparta, North Carolina.
Earthquakes large enough to be felt occur approximately once per year in the ETSZ.
[1] The United States Geological Survey estimates that earthquakes as large as magnitude 7.5 are possible in the ETSZ.
The ETSZ is located far from edge of the North American plate and represents a mid-continent or intraplate earthquake zone.