QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Trinidad, CO

No earthquake was likely felt in Trinidad in the 24 hours to 10:39 am MST (17:39 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 1.7 earthquake was recorded 15 km (10 mi) north of Trinidad, CO, at 1:56 am MST on 9 December 2023 (08:56 UTC), 5.0 km deep.

USGS: 9 km NNW of El Moro, Colorado

1:56 am MST, Dec 9, 2023 · · 5.0 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Las Animas County 40 kmHuerfano County 59 kmColfax County 78 kmCostilla County 82 kmOtero County 94 kmPueblo County 95 kmCuster County 117 kmAlamosa 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
1:56 am MST on 9 December 2023 ()
Where
15 km (10 mi) north of Trinidad, CO · earthquakes near Trinidad
Magnitude
M 1.7 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Las Animas County, 40 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1005 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 11 km (7 mi) from the epicentre. In Trinidad, 15 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.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 7,900 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.3 6 km S of Valdez, Colorado · 33 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 37.3088, -104.4973. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Las Animas County, CO 40 km (25 mi) E earthquakes near Las Animas County
Huerfano County, CO 59 km (36 mi) NW earthquakes near Huerfano County
Colfax County, NM 78 km (49 mi) S earthquakes near Colfax County
Costilla County, CO 82 km (51 mi) W earthquakes near Costilla County
Otero County, CO 94 km (58 mi) NE earthquakes near Otero County
Pueblo County, CO 95 km (59 mi) N earthquakes near Pueblo County

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

Aftershocks so far

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

  1. 2.4 20 km S of Weston, Colorado
  2. 1.5 19 km S of Weston, Colorado
  3. 1.8 8 km NNW of El Moro, Colorado
  4. 1.9 17 km S of Weston, Colorado
  5. 1.6 10 km NNW of El Moro, Colorado
  6. 1.5 18 km S of Weston, Colorado
  7. 2.1 18 km S of Weston, Colorado
  8. 1.7 18 km S of Weston, Colorado
  9. 2.0 13 km SW of Weston, Colorado
  10. 1.9 10 km NNW of El Moro, Colorado
  11. 1.7 16 km S of Weston, Colorado
  12. 2.5 6 km NNW of El Moro, Colorado
  13. 1.6 9 km NNW of El Moro, Colorado
  14. 1.5 9 km NNW of El Moro, Colorado
  15. 2.1 8 km N of El Moro, 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.