QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Trinidad, CO

No earthquake was likely felt in Trinidad in the 24 hours to 5:29 am MST (12:29 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 1.8 earthquake was recorded 43 km (27 mi) west-southwest of Trinidad, CO, at 11:04 am MDT on 11 August 2020 (17:04 UTC), 6.5 km deep.

USGS: 14 km SW of Weston, Colorado

11:04 am MDT, Aug 11, 2020 · · 6.5 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Costilla County 51 kmColfax County 53 kmHuerfano County 74 kmTaos County 79 kmLas Animas County 86 kmAlamosa County 96 kmConejos County 111 kmMora County 116 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
11:04 am MDT on 11 August 2020 ()
Where
43 km (27 mi) west-southwest of Trinidad, CO · earthquakes near Trinidad
Magnitude
M 1.8 (ml)
Depth
6.5 km below the surface
Felt
no reports yet
Nearest
Costilla County, 51 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2212 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 15 km (9 mi) from the epicentre. In Trinidad, 43 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 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.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. 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

The largest earthquake within 50 km since 2016 was M 4.2 on 2016-12-23 — about 4,000 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 · 22 km E of this epicentre
  2. 5.0 20 km S of Weston, Colorado · 13 km SE 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 37.0252, -104.9470. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Costilla County, CO 51 km (32 mi) WNW earthquakes near Costilla County
Colfax County, NM 53 km (33 mi) SSE earthquakes near Colfax County
Huerfano County, CO 74 km (46 mi) N earthquakes near Huerfano County
Taos County, NM 79 km (49 mi) SW earthquakes near Taos County
Las Animas County, CO 86 km (54 mi) ENE earthquakes near Las Animas County
Alamosa County, CO 96 km (60 mi) NW earthquakes near Alamosa County

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

Aftershocks so far

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

  1. 2.0 6 km NNW of El Moro, Colorado
  2. 2.4 19 km S of Weston, Colorado
  3. 2.7 31 km S of Segundo, Colorado
  4. 1.5 13 km NNW of Cokedale, Colorado
  5. 3.0 Colorado
  6. 1.6 15 km W of Aguilar, Colorado
  7. 1.5 13 km SSE of Stonewall Gap, Colorado
  8. 1.9 15 km SSW of Weston, Colorado
  9. 2.3 15 km SW of Weston, Colorado
  10. 1.7 13 km SSE of Stonewall Gap, Colorado
  11. 1.6 13 km SSE of Stonewall Gap, Colorado
  12. 1.6 17 km SSE of Stonewall Gap, Colorado
  13. 2.3 28 km NNE of Ute Park, New Mexico
  14. 2.6 23 km NE of Ute Park, New Mexico
  15. 4.0 25 km N of Cimarron, New Mexico

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.