QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Tennessee-North Carolina border region

Yes. A magnitude 2.5 earthquake was recorded in the Tennessee-North Carolina border region, 16 km (10 mi) SSE of Knoxville, TN, at 1:44 am EST on 8 December 2021 (06:44 UTC), 9.1 km deep. 22 people have reported feeling it to USGS.

16 km (10 mi) SSE of Knoxville, TN

· 9.1 km deep · released about 160 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Blount County 17 kmKnox County 18 kmSevier County 33 kmLoudon County 40 kmAnderson County 42 kmJefferson County 46 kmSwain County 48 kmUnion County 49 kmMonroe County 55 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 2.5 (md)
Depth
9.1 km below the surface
Felt
22 reports · strongest reported intensity IV
Nearest
Blount County, 17 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1733 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 44 km (27 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Maryville 12 km, intensity III · Knoxville 14 km, intensity III · Seymour 15 km, intensity III · Farragut 25 km, intensity II · Mascot 27 km, intensity II · Sevierville 29 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 160 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 95,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 68,000× the energy of this one
  3. Around the size people start to feel M 3.0 6× the energy of this one
  4. This earthquake M 2.5 about 160 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

Where

Epicentre 35.8410, -83.8845. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Blount County, TN 17 km (11 mi) SSW earthquakes near Blount County
Knox County, TN 18 km (11 mi) NNW earthquakes near Knox County
Sevier County, TN 33 km (20 mi) E earthquakes near Sevier County
Loudon County, TN 40 km (25 mi) WSW earthquakes near Loudon County
Anderson County, TN 42 km (26 mi) NW earthquakes near Anderson County
Jefferson County, TN 46 km (29 mi) ENE earthquakes near Jefferson County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

49 earthquakes have been recorded within 50 km since this one.

  1. 2.0 17 km WNW of Bryson City, North Carolina
  2. 1.7 17 km WNW of Bryson City, North Carolina
  3. 2.1 17 km WNW of Bryson City, North Carolina
  4. 2.0 17 km WNW of Bryson City, North Carolina
  5. 2.0 13 km SE of Greenback, Tennessee
  6. 1.6 7 km SSE of Vonore, Tennessee
  7. 1.7 8 km E of Greenback, Tennessee
  8. 1.9 1 km WSW of Plainview, Tennessee
  9. 2.2 9 km W of Clinton, Tennessee
  10. 1.6 1 km SSW of Eagleton Village, Tennessee
  11. 2.0 Tennessee-North Carolina border region
  12. 2.4 Kentucky-Tennessee border region
  13. 2.4 10 km SW of Gatlinburg, Tennessee
  14. 2.1 6 km WSW of Tellico Village, Tennessee
  15. 2.4 Tennessee-North Carolina border region

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.