Earthquake · reviewed by a seismologist
M 1.8md
Tennessee
Yes. A magnitude 1.8 earthquake was recorded in Tennessee, 70 km (44 mi) ENE of Chattanooga, TN, at 8:39 am EDT on 20 September 2018 (12:39 UTC), 11 km deep.
70 km (44 mi) ENE of Chattanooga, TN · 34 km (21 mi) ENE of Cleveland, TN
- When
- Magnitude
- M 1.8 (md)
- Depth
- 11 km below the surface
- Felt
- no reports yet
- Nearest
- Polk County, 15 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2974 days ago
Earthquake alerts for Etowah, TN
Get a notification in this browser when USGS records an earthquake near Etowah, 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, people at rest would likely notice it out to about 12 km (7 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.
Earthquakes near other towns within 30 km: Etowah, Benton, Athens.
How big was it?
This earthquake released about 15 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 1,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 730,000× the energy of this one
- Around the size people start to feel M 3.0 65× the energy of this one
- This earthquake M 1.8 about 15 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
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 35.2393, -84.5058. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Polk County, TN | 15 km (9 mi) | SSW | earthquakes near Polk County |
| McMinn County, TN | 23 km (14 mi) | NNW | earthquakes near McMinn County |
| Monroe County, TN | 33 km (20 mi) | NE | earthquakes near Monroe County |
| Bradley County, TN | 34 km (21 mi) | WSW | earthquakes near Bradley County |
| Meigs County, TN | 41 km (26 mi) | NW | earthquakes near Meigs County |
| Cherokee County, NC | 42 km (26 mi) | ESE | earthquakes near Cherokee County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 1.8 6 km SW of Tellico Plains, Tennessee
- 2.5 6 km ENE of Decatur, Tennessee
- 2.0 3 km WNW of Madisonville, Tennessee
- 2.1 14 km NNE of Mineral Bluff, Georgia
- 2.1 6 km WNW of Vonore, Tennessee
- 2.3 6 km SE of Englewood, Tennessee
- 1.7 10 km SSE of Vonore, Tennessee
- 1.6 8 km SSE of Vonore, Tennessee
- 2.3 12 km SSE of Tellico Plains, Tennessee
- 1.7 6 km WSW of Tellico Village, Tennessee
- 1.6 19 km S of Tellico Plains, Tennessee
- 2.1 2 km W of Hopewell, Tennessee
- 2.1 4 km NW of Tellico Plains, Tennessee
- 1.7 5 km NW of Tellico Plains, Tennessee
- 1.9 6 km SW of Tellico Village, 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.