A M3.4 earthquake hit near Maynardville on Tuesday, March 5, 2019. Originally M3.3, it was upgraded to M3.4 by USGS. More than 1600 people have reported feeling the shallow earthquake (17.1km; 10.6miles). Loud booms, house shaking and small damage reported up to Knoxville.
It happened around 4 p.m. As of about 5:30 p.m., USGS said 1,235 people had reported it to them.
The “TV shook, and the bed shook,” said a Jefferson County resident who called WVLT News to report the quake.
Beverly Clark, of Union County, sent a picture of a broken light fixture, damaged in the quake. “I have been in a few earthquakes, but I have NEVER heard the BOOM this one made,” she said. Clark also said her house shook twice and made a ceiling tile in the basement fall.
“The whole house shook,” said a Washburn resident, “I blamed my husband, thought he was doing something with the chainsaw.“
A resident in Fountain City reported feeling it. “The house literally shook,” she said. “There was a noise with it.“
So what are the BOOMS?
You may hear sounds with earthquakes. According to the USGS, many people report hearing loud “booms” along with seismic activity.
“No one knows for sure, but scientists speculate that these “booms” are probably small shallow earthquakes that are too small to be recorded, but large enough to be felt by people nearby,” USGS says.
Knoxville and surrounding areas sit along the East Tennessee Seismic Zone (ETSZ), one of the most active earthquake zones in the eastern United States. Most local earthquakes are ‘weaker,’ but some people will still feel the ground shaking if the magnitude is 2.5 or higher.
A few damaging earthquakes have occurred in the ETSZ. The largest historic earthquakes measured M4.6 and hit 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.
The source of seismic activity in the ETSZ is not known. The ETSZ is located far from edge of the North American continent and represents a mid-continent or intraplate earthquake zone. The known faults in the ETSZ are generally ancient; no known active faults reach the surface.
Yesterday’s earthquake, about 33 miles northeast of Knoxville, follows a 2.2 magnitude quake near Kingston on Feb. 22, a 2.2 magnitude quake near Morristown on Feb. 8 and a 2.5 magnitude earthquake near Rutledge on Feb. 4.