QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4mb_lg

Earthquake near Trinidad, CO

No earthquake was likely felt in Trinidad in the 24 hours to 1:29 am MST (08:29 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 3.4 earthquake was recorded 40 km (25 mi) west-northwest of Trinidad, CO, at 9:41 pm MST on 19 December 2017 (04:41 UTC), 2.1 km deep. 5 people have reported feeling it to USGS.

USGS: 18 km NNE of Stonewall Gap, Colorado

9:41 pm MST, Dec 19, 2017 · · 2.1 km deep · released about 1.9 tons of TNT

Every earthquake near Trinidad Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Costilla County 44 kmHuerfano County 44 kmLas Animas County 78 kmColfax County 79 kmAlamosa County 82 kmCuster County 99 kmTaos County 101 kmPueblo County 105 kmConejos County 111 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
9:41 pm MST on 19 December 2017 ()
Where
40 km (25 mi) west-northwest of Trinidad, CO · earthquakes near Trinidad
Magnitude
M 3.4 (mb_lg)
Depth
2.1 km below the surface
Felt
5 reports · strongest reported intensity IV
Nearest
Costilla County, 44 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3164 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 271 km (168 mi) from the epicentre. In Trinidad, 40 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: Walsenburg 39 km, intensity III · Trinidad 40 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4× more

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 4.0 on 2016-02-06 — about 7.9 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 · 32 km SE of this epicentre
  2. 5.0 20 km S of Weston, Colorado · 39 km SSE 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 37.2887, -104.9265. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Costilla County, CO 44 km (28 mi) W earthquakes near Costilla County
Huerfano County, CO 44 km (28 mi) N earthquakes near Huerfano County
Las Animas County, CO 78 km (49 mi) E earthquakes near Las Animas County
Colfax County, NM 79 km (49 mi) SSE earthquakes near Colfax County
Alamosa County, CO 82 km (51 mi) WNW earthquakes near Alamosa County
Custer County, CO 99 km (61 mi) NNW earthquakes near Custer County

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

Aftershocks so far

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

  1. 1.5 13 km SSE of Stonewall Gap, Colorado
  2. 1.9 16 km SSW of Weston, Colorado
  3. 1.6 17 km SSW of Weston, Colorado
  4. 1.5 13 km SSE of Stonewall Gap, Colorado
  5. 2.0 13 km SSE of Stonewall Gap, Colorado
  6. 1.6 12 km SSE of Stonewall Gap, Colorado
  7. 1.6 16 km SSW of Weston, Colorado
  8. 1.8 16 km S of Stonewall Gap, Colorado
  9. 1.7 14 km SSE of Stonewall Gap, Colorado
  10. 2.1 16 km SSE of Stonewall Gap, Colorado
  11. 2.8 16 km SSE of Stonewall Gap, Colorado
  12. 1.6 15 km SSE of Stonewall Gap, Colorado
  13. 3.1 15 km SSE of Stonewall Gap, Colorado
  14. 1.5 13 km SSE of Stonewall Gap, Colorado
  15. 3.8 15 km SSE of Stonewall Gap, 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.