QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Colorado City, CO

No earthquake was likely felt in Colorado City in the 24 hours to 7:15 am MST (14:15 UTC). The last one was M 3.4, 97 km (60 mi) S, at 3:34 am MST on 8 November 2026, estimated intensity II (weak) in town; 2 felt reports to USGS. Every earthquake near Colorado City

This page: a magnitude 1.6 earthquake was recorded 14 km (9 mi) east-northeast of Colorado City, CO, at 6:52 pm MDT on 29 September 2023 (00:52 UTC), 5.0 km deep.

USGS: 13 km ENE of Colorado City, Colorado

100 km (62 mi) S of Colorado Springs, CO · 34 km (21 mi) S of Pueblo, CO

6:52 pm MDT, Sep 29, 2023 · · 5.0 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N Pueblo County 27 kmHuerfano County 40 kmCuster County 62 kmFremont County 84 kmOtero County 85 kmCrowley County 88 kmLas Animas County 92 kmEl Paso County 96 kmCostilla County 101 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
6:52 pm MDT on 29 September 2023 ()
Where
14 km (9 mi) east-northeast of Colorado City, CO · earthquakes near Colorado City
Magnitude
M 1.6 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Pueblo County, 27 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1068 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 6 km (4 mi) from the epicentre. In Colorado City, 14 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 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 37.9713, -104.6800. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Pueblo County, CO 27 km (17 mi) NE earthquakes near Pueblo County
Huerfano County, CO 40 km (25 mi) SW earthquakes near Huerfano County
Custer County, CO 62 km (39 mi) WNW earthquakes near Custer County
Fremont County, CO 84 km (52 mi) NW earthquakes near Fremont County
Otero County, CO 85 km (53 mi) E earthquakes near Otero County
Crowley County, CO 88 km (54 mi) ENE earthquakes near Crowley County

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

Aftershocks so far

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

  1. 1.8 10 km SW of Walsenburg, Colorado
  2. 1.5 10 km SW of Walsenburg, Colorado
  3. 2.4 10 km SW of Walsenburg, Colorado
  4. 2.7 8 km SW of Walsenburg, Colorado
  5. 2.5 12 km NNW of Walsenburg, Colorado
  6. 2.9 5 km SSW of Walsenburg, Colorado
  7. 2.3 7 km SW of Walsenburg, Colorado
  8. 2.3 5 km SSW of Walsenburg, Colorado
  9. 2.4 15 km ENE of Colorado City, Colorado
  10. 1.8 21 km WSW of Beulah Valley, Colorado
  11. 2.6 21 km ESE of Colorado City, Colorado
  12. 1.6 16 km E of Colorado City, Colorado
  13. 1.7 10 km SE of Walsenburg, Colorado
  14. 1.7 11 km SSE of Walsenburg, 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.