QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

3 km E of Philadelphia, Tennessee

· 18 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Loudon County 8 kmRoane County 24 kmMonroe County 28 kmMcMinn County 36 kmBlount County 40 kmMeigs County 45 kmAnderson County 51 kmKnox County 52 kmRhea County 53 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 1.8 (md)
Depth
18 km below the surface
Felt
no reports yet
Nearest
Loudon County, 8 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 358 days ago

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

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 35.6767, -84.3672. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Loudon County, TN 8 km (5 mi) SW of here earthquakes near Loudon County
Roane County, TN 24 km (15 mi) SE of here earthquakes near Roane County
Monroe County, TN 28 km (17 mi) NNW of here earthquakes near Monroe County
McMinn County, TN 36 km (22 mi) NE of here earthquakes near McMinn County
Blount County, TN 40 km (25 mi) W of here earthquakes near Blount County
Meigs County, TN 45 km (28 mi) ENE of here earthquakes near Meigs County

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

Aftershocks so far

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

  1. 2.1 5 km NNE of Greenback, Tennessee
  2. 2.0 1 km S of Tellico Village, Tennessee
  3. 2.1 1 km S of Tellico Village, Tennessee
  4. 1.7 1 km ENE of Sweetwater, Tennessee
  5. 1.8 11 km NNE of Decatur, Tennessee
  6. 2.4 10 km NNE of Decatur, Tennessee
  7. 2.0 3 km SW of Tellico Village, Tennessee
  8. 1.6 8 km E of Englewood, Tennessee
  9. 1.8 8 km E of Englewood, Tennessee
  10. 2.2 9 km S of Oak Ridge, Tennessee
  11. 2.0 8 km SSE of Etowah, Tennessee
  12. 1.7 6 km WNW of Sweetwater, Tennessee
  13. 1.9 4 km W of Etowah, Tennessee
  14. 2.0 2 km SW of Vonore, Tennessee
  15. 2.4 2 km SW of Vonore, Tennessee

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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.4 on 2018-12-12 — it released about 9,400 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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