Earthquake · reviewed by a seismologist
M 3.0ml
Colorado
Yes. A magnitude 3.0 earthquake was recorded in Colorado, at 11:20 am MDT on 17 August 2023 (17:20 UTC), 5.0 km deep. 4 people have reported feeling it to USGS.
- When
- Magnitude
- M 3.0 (ml)
- Depth
- 5.0 km below the surface
- Felt
- 4 reports · strongest reported intensity V
- Measured shaking
- intensity IV (ShakeMap)
- Nearest
- Huerfano County, 57 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1111 days ago
Earthquake alerts for Trinidad, CO
Get a notification in this browser when USGS records an earthquake near Trinidad, CO. No account or email needed.
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 73 km (45 mi) from the epicentre. 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 23 km, intensity III · Raton 44 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 350,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
- Magna, Utah 2020 M 5.7 11,000× the energy of this one
- This earthquake M 3.0 about 950 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 89 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 · 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 37.1986, -104.7623. 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 | 60 km (37 mi) | W | earthquakes near Costilla County |
| Las Animas County, CO | 65 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 | 104 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.
- 1.7 11 km NE of Stonewall Gap, Colorado
- 1.7 6 km WNW of Hoehne, Colorado
- 1.5 13 km S of Stonewall Gap, Colorado
- 1.5 15 km SSW of Weston, Colorado
- 1.7 10 km SE of Walsenburg, Colorado
- 1.7 11 km SSE of Walsenburg, Colorado
- 1.9 23 km S of Weston, Colorado
- 1.6 12 km S of Weston, Colorado
- 1.5 10 km SSE of Walsenburg, Colorado
- 2.2 Colorado
- 1.6 Colorado
- 1.6 9 km WNW of Hoehne, Colorado
- 2.8 7 km NNW of El Moro, Colorado
- 1.5 Colorado
- 1.5 8 km N 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
- 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.