Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Loudon, TN
No earthquake was likely felt in Loudon in the 24 hours to 3:27 pm EST (20:27 UTC). The last one was M 2.4, 14 km (8 mi) N, at 1:54 am EDT on 30 October 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Loudon
This page: a magnitude 1.8 earthquake was recorded 5 km (3 mi) south-southwest of Loudon, TN, at 7:54 am EDT on 21 May 2023 (11:54 UTC), 20 km deep.
USGS: 4 km SSW of Loudon, Tennessee
47 km (30 mi) SW of Knoxville, TN
- When
- 7:54 am EDT on 21 May 2023 ()
- Where
- 5 km (3 mi) south-southwest of Loudon, TN · earthquakes near Loudon
- Magnitude
- M 1.8 (md)
- Depth
- 20 km below the surface
- Felt
- no reports yet
- Nearest
- Loudon County, 6 km NNE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1028 days ago
Earthquake alerts for Loudon, TN
Get a notification in this browser when USGS records an earthquake near Loudon, TN. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. In Loudon, 5 km away, the estimate is intensity II (weak). 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.
Earthquakes near other towns within 30 km: Tellico Village, Sweetwater, Lenoir City, Vonore, Greenback, Madisonville.
How big was it?
This earthquake released about 17 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.
- Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
- Magna, Utah 2020 M 5.7 640,000× the energy of this one
- Around the size people start to feel M 3.0 57× the energy of this one
- This earthquake M 1.8 about 17 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.
For this area
The largest earthquake within 50 km since 2016 was M 4.4 on 2018-12-12 — about 7,200 times the energy of this one.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 35.6922, -84.3485. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Loudon County, TN | 6 km (4 mi) | NNE | earthquakes near Loudon County |
| Roane County, TN | 23 km (15 mi) | NW | earthquakes near Roane County |
| Monroe County, TN | 29 km (18 mi) | SSE | earthquakes near Monroe County |
| Blount County, TN | 38 km (24 mi) | E | earthquakes near Blount County |
| McMinn County, TN | 39 km (24 mi) | SW | earthquakes near McMinn County |
| Meigs County, TN | 47 km (29 mi) | WSW | earthquakes near Meigs County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 1.8 2 km NE of Greenback, Tennessee
- 2.1 16 km SE of Vonore, Tennessee
- 2.2 4 km N of Englewood, Tennessee
- 1.9 2 km NE of Greenback, Tennessee
- 2.3 2 km NE of Greenback, Tennessee
- 2.0 6 km ENE of Etowah, Tennessee
- 1.7 4 km ENE of Niota, Tennessee
- 2.1 3 km ENE of Niota, Tennessee
- 2.1 6 km E of Friendsville, Tennessee
- 1.7 6 km SSE of Friendsville, Tennessee
- 1.6 16 km SE of Vonore, Tennessee
- 1.8 4 km SSW of Tellico Village, Tennessee
- 1.9 1 km WNW of Tellico Village, Tennessee
- 2.3 1 km NW of Niota, Tennessee
- 1.7 7 km SW of Maryville, 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.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.