Earthquake · reviewed by a seismologist
M 3.6mwr
Earthquake near Trinidad, CO
No earthquake was likely felt in Trinidad in the 24 hours to 1:06 pm MST (20:06 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 3.6 earthquake was recorded 25 km (16 mi) west of Trinidad, CO, at 5:46 pm MDT on 10 September 2023 (23:46 UTC), 2.0 km deep. 26 people have reported feeling it to USGS.
USGS: 8 km NNW of Segundo, Colorado
- When
- 5:46 pm MDT on 10 September 2023 ()
- Where
- 25 km (16 mi) west of Trinidad, CO · earthquakes near Trinidad
- Magnitude
- M 3.6 (mwr)
- Depth
- 2.0 km below the surface
- Felt
- 26 reports · strongest reported intensity VI
- Measured shaking
- intensity V (ShakeMap)
- Nearest
- Huerfano County, 57 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1089 days ago
Earthquake alerts for Trinidad, CO
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 339 km (211 mi) from the epicentre. In Trinidad, 25 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 25 km, intensity III · Raton 45 km, intensity III · Walsenburg 48 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 45,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400× the energy of this one
- This earthquake M 3.6 about 3.8 tons of TNT
- Around the size people start to feel M 3.0 this one released 7.9× 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 4.3 on 2023-03-10 — about 11 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.3 6 km S of Valdez, Colorado · 16 km SSE of this epicentre
- 5.0 20 km S of Weston, Colorado · 28 km S 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 37.1967, -104.7813. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Huerfano County, CO | 57 km (35 mi) | NNW | earthquakes near Huerfano County |
| Costilla County, CO | 58 km (36 mi) | W | earthquakes near Costilla County |
| Colfax County, NM | 66 km (41 mi) | S | earthquakes near Colfax County |
| Las Animas County, CO | 67 km (41 mi) | ENE | earthquakes near Las Animas County |
| Alamosa County, CO | 98 km (61 mi) | WNW | earthquakes near Alamosa County |
| Taos County, NM | 103 km (64 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.
- 1.6 6 km NNW of Hoehne, Colorado
- 1.7 8 km NNE of Weston, Colorado
- 1.7 8 km N of Valdez, Colorado
- 2.2 24 km S of Weston, Colorado
- 1.5 27 km SSW of Segundo, Colorado
- 1.6 12 km S of Stonewall Gap, Colorado
- 1.6 14 km SSE of Stonewall Gap, Colorado
- 1.9 11 km SE of Stonewall Gap, Colorado
- 3.3 14 km SSE of Stonewall Gap, Colorado
- 1.7 8 km N of Segundo, Colorado
- 3.0 7 km N of Segundo, Colorado
- 1.5 1 km S of El Moro, Colorado
- 1.5 27 km SSW of Segundo, Colorado
- 3.8 31 km S of Segundo, Colorado
- 1.6 6 km NW of Hoehne, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.