South Holston earthquake
The University of Memphis - Center for Earthquake Research & Information, reports an earthquake on Sunday (Nov 21, 2021) at about 06:04:12 EST, near Bristol, Tennessee 9.87 km south of Abingdon, Virginia. The earthquake could be felt in the South Holston Lake area.
According to USGS reports, the quake was centered at a depth of 2.8 miles, just off Creamery Drive. with a magnitude of 2.6 on the richter scale. The USGS asks that anyone in the area at the time submit a citizen science report to USGS here, describing what they felt at the time of the event.
At 9 A.M. this morning (November 21, 2021), the Community Survey Data reports the impact "Level 3" - weak without damage, according the the USGS.
Another earthquake measuring 2.3 magnitude was registered in Maryville, Tennessee a few hours later around 1 P.M. Sunday afternoon (November 21, 2021). USGS reports the quake could be felt as far away as Farragut, Knoxville, and Seymour, Tennessee.
Tennessee Earthquakes on the Rise?
Tennessee's had four "significant" earthquakes in the past few decades, according to the U.S. Geological Survey. In an interview with the Tennessean in 2019, Tennessee geologist Ronald Zurawski said the state may not be experiencing more earthquakes. It could be more people are just reporting they felt them.
"We have more seismic sensing devices than we used to. We are picking up smaller earthquakes, and people are becoming more aware of the hazard.."- Ronald Zurawski, Geologist
The state is divided into two seismic zones: the New Madrid in West Tennessee and the East Tennessee seismic zone. "Earthquakes are very complex," Zurawski said in his interview with the Tennessean. "It’s not like a pebble in a pond. It happens in an irregular pattern."
Earthquakes common to Tennessee
In 2018, Tennessee had over 300 earthquakes, the highest amount in the past 25 years, according to USGS data. In comparison, California has thousands of earthquakes each year. Tectonic plate movement less than 2.5 is seldom felt.
We are most all familiar with Reel Foot Lake in Western Tennessee, caused by the historic 1811 earthquake along the new Madrid Fault. It was the largest on record in Tennessee, and was a 7.5 magnitude earthquake, causing the Mississippi River to flow backward, as the lake was formed. While scientists say it's likely that Tennessee will experience another such earthquake, they are unable to forecast when such an event will likely occur.
Mitigation efforts in the Memphis and western areas of the state are well underway, with building codes enacted to make most structures more resilient to earthquake activity. As with life everywhere, it's just a waiting game. We need only be prepared - just in case.