2011 Virginia earthquake
The USGS found that the farthest landslide from the 2011 Virginia earthquake was from the epicenter. This is by far the greatest landslide distance recorded from any other earthquake of similar magnitude. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than from the epicenter of a magnitude 5.8 earthquake. The study suggested that the added information about East Coast earthquakes may prompt a revision of equations that predict ground shaking. "What makes this new study so unique is that it provides direct observational evidence from the largest earthquake to occur in more than 100 years in the eastern U.S. Now that we know more about the power of East Coast earthquakes, equations that predict ground shaking might need to be revised."
Eastern Tennessee Seismic Zone
Most earthquakes in the ETSZ are small and are detected only with instruments. A few damaging earthquakes have occurred in the ETSZ; the largest historic earthquakes measured 4.6 magnitude, occurring in 1973 near Knoxville, Tennessee and April 29, 2003 near Fort Payne, Alabama. Earthquakes large enough to be felt occur approximately once a year in the ETSZ. The U.S. Geological Survey estimates that earthquakes as large as magnitude 7.5 are possible in the ETSZ. Events of magnitude 5–6 are estimated to occur once every 200 to 300 years.