QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

Earthquake near Trinidad, CO

No earthquake was likely felt in Trinidad in the 24 hours to 7:09 am MST (14:09 UTC). The last one was M 3.4, 45 km (28 mi) WSW, at 3:34 am MST on 8 November 2026, estimated intensity III (weak) in town; 2 felt reports to USGS. Every earthquake near Trinidad

This page: a magnitude 2.9 earthquake was recorded 22 km (14 mi) west of Trinidad, CO, at 5:09 pm MDT on 18 March 2023 (23:09 UTC), 6.5 km deep. 10 people have reported feeling it to USGS.

USGS: 8 km N of Segundo, Colorado

5:09 pm MDT, Mar 18, 2023 · · 6.5 km deep · released about 680 lb of TNT

10 km30 km60 km120 km N Huerfano County 57 kmCostilla County 61 kmLas Animas County 64 kmColfax County 66 kmAlamosa County 100 kmTaos County 105 kmPueblo County 110 kmCuster County 114 kmOtero County 118 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
5:09 pm MDT on 18 March 2023 ()
Where
22 km (14 mi) west of Trinidad, CO · earthquakes near Trinidad
Magnitude
M 2.9 (ml)
Depth
6.5 km below the surface
Felt
10 reports · strongest reported intensity IV
Nearest
Huerfano County, 57 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1271 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 67 km (42 mi) from the epicentre. In Trinidad, 22 km away, the estimate is intensity III (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.

Likely felt in: Trinidad 22 km, intensity III · Raton 43 km, intensity II · Walsenburg 47 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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 4.3 on 2023-03-10 — about 130 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.3 6 km S of Valdez, Colorado · 16 km SSE of this epicentre
  2. 5.0 20 km S of Weston, Colorado · 29 km SSW of this epicentre

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 37.1994, -104.7497. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Huerfano County, CO 57 km (36 mi) NNW earthquakes near Huerfano County
Costilla County, CO 61 km (38 mi) W earthquakes near Costilla County
Las Animas County, CO 64 km (40 mi) ENE earthquakes near Las Animas County
Colfax County, NM 66 km (41 mi) S earthquakes near Colfax County
Alamosa County, CO 100 km (62 mi) WNW earthquakes near Alamosa County
Taos County, NM 105 km (65 mi) SW earthquakes near Taos County

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

Aftershocks so far

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

  1. 2.8 12 km SW of Weston, Colorado
  2. 2.1 Colorado
  3. 1.9 8 km N of El Moro, Colorado
  4. 1.6 21 km ENE of Lynn, Colorado
  5. 1.8 7 km N of El Moro, Colorado
  6. 4.1 Colorado
  7. 3.4 7 km NNW of El Moro, Colorado
  8. 1.6 11 km SSE of Stonewall Gap, Colorado
  9. 2.3 8 km N of El Moro, Colorado
  10. 1.5 16 km S of Weston, Colorado
  11. 1.7 16 km S of Weston, Colorado
  12. 1.6 21 km S of Segundo, Colorado
  13. 1.7 15 km S of Weston, Colorado
  14. 2.9 30 km S of Sequndo, Colorado
  15. 1.5 32 km S of Segundo, Colorado

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.