QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Trinity, AL

No earthquake was likely felt in Trinity in the 24 hours to 10:46 am CST (16:46 UTC). The last one was M 2.5, 12 km (8 mi) NNE, at 10:54 pm CDT on 26 April 2026, estimated intensity III (weak) in town; 2 felt reports to USGS. Every earthquake near Trinity

This page: a magnitude 2.1 earthquake was recorded 8 km (5 mi) southwest of Trinity, AL, at 12:57 pm CST on 14 December 2017 (18:57 UTC), 5.0 km deep.

USGS: 8 km SW of Trinity, Alabama

47 km (29 mi) WSW of Huntsville, AL · 15 km (10 mi) W of Decatur, AL

12:57 pm CST, Dec 14, 2017 · · 5.0 km deep · released about 37 lb of TNT

10 km30 km60 km120 km N Lawrence County 15 kmMorgan County 31 kmLimestone County 32 kmWinston County 49 kmCullman County 55 kmLauderdale County 59 kmMadison County 60 kmColbert County 61 kmFranklin County 64 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
12:57 pm CST on 14 December 2017 ()
Where
8 km (5 mi) southwest of Trinity, AL · earthquakes near Trinity
Magnitude
M 2.1 (md)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Lawrence County, 15 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3253 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 26 km (16 mi) from the epicentre. In Trinity, 8 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: Moulton, Decatur, Danville, Flint City, Hartselle, Priceville.

How big was it?

This earthquake released about 37 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 34.5608, -87.1573. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lawrence County, AL 15 km (10 mi) WSW earthquakes near Lawrence County
Morgan County, AL 31 km (19 mi) ESE earthquakes near Morgan County
Limestone County, AL 32 km (20 mi) NNE earthquakes near Limestone County
Winston County, AL 49 km (30 mi) SSW earthquakes near Winston County
Cullman County, AL 55 km (34 mi) SSE earthquakes near Cullman County
Lauderdale County, AL 59 km (37 mi) NW earthquakes near Lauderdale County

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

Aftershocks so far

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

  1. 2.5 12 km NNE of Trinity, Alabama
  2. 2.3 5 km NW of Addison, Alabama
  3. 2.4 6 km NW of Addison, Alabama
  4. 2.3 13 km N of Double Springs, Alabama
  5. 2.1 3 km NE of Courtland, Alabama
  6. 2.6 13 km SE of Triana, Alabama
  7. 2.5 13 km S of Moulton, Alabama
  8. 2.3 8 km S of Killen, Alabama

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.