Fourth Earthquake Strikes Tennessee in Four Days Today

The epicenter of today's earthquake is at the orange dot inside the colored concentric circles on this map. Image: USGS — The epicenter of today’s earthquake is at the orange dot inside the colored concentric circles on this map. Image: USGS

For the fourth time in the last 4 days days, another relatively weak earthquake has hit eastern Tennessee giving people a gentle shake there. According to USGS, at 7:41 am this morning a magnitude 2.3 earthquake struck from a depth of 2.8 km near the town of Rutledge which is roughly 30 miles northeast of Knoxville, Tennessee. The prior earthquakes in the last few days also struck not far from Knoxville, with epicenters recorded in Mascot on Monday, Tellico Village on Tuesday, and Greenback on Wednesday. Today’s earthquake was the largest of the four to strike eastern Tennessee this week

USGS says that earthquakes with a magnitude of 2.0 or less are rarely felt or heard by people, but once they exceed 2.0 , more and more people can feel them. While damage is possible with magnitude 3.0 events or greater, significant damage and casualties usually don’t occur until the magnitude of a seismic event rises to a 5.5 or greater rated event.

While the U.S. West Coast is best known for their earthquakes, there is considerable earthquake risk elsewhere in the country. Image: USGS

Earthquakes like the one that hit this morning in the eastern part of Tennessee are unlikely associated with the New Madrid Seismic Zone, an area of ongoing seismic activity located near the Mississippi River. However, while USGS says western Tennessee has a higher frequency of damaging earthquake shaking, the risk isn’t that low in eastern Tennessee. In the area of this most recent quake, USGS says its likely this area would see 50-100 damaging earthquakes over 10,000 years. While this number is low, it is much higher than it is elsewhere in the eastern half of the United States, where it’s likely to have 10 or less earthquakes over the same period.

The primary emergency advice for an earthquake in Tennessee is to “Drop, Cover, and Hold On” the moment one feels the ground shake. Because Tennessee sits directly between two active fault areas—the New Madrid Seismic Zone in the west and the East Tennessee Seismic Zone in the east—the Tennessee Emergency Management Agency (TEMA) emphasizes being physically and financially prepared for a sudden tremor.

According to USGS, the number of earthquakes in Tennessee is increasing over time. USGS says that the number of earthquakes in Tennessee hovered around just 30-50 per year during the mid-to-late 1990s. That number increased to approximately 150 in the mid-2000s and shot up to nearly 300 in the late 2010s.