QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Alamosa, CO

No earthquake was likely felt in Alamosa in the 24 hours to 8:31 am MST (15:31 UTC). The last one was M 3.4, 89 km (55 mi) ESE, at 3:34 am MST on 8 November 2026, estimated intensity II (weak) in town; 2 felt reports to USGS. Every earthquake near Alamosa

This page: a magnitude 1.5 earthquake was recorded 38 km (24 mi) east-northeast of Alamosa, CO, at 1:14 am MST on 15 December 2022 (08:14 UTC), 5.0 km deep.

USGS: 22 km N of Blanca, Colorado

1:14 am MST, Dec 15, 2022 · · 5.0 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N Alamosa County 27 kmCostilla County 40 kmHuerfano County 47 kmCuster County 53 kmConejos County 77 kmSaguache County 79 kmRio Grande County 87 kmFremont County 91 kmPueblo County 106 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
1:14 am MST on 15 December 2022 ()
Where
38 km (24 mi) east-northeast of Alamosa, CO · earthquakes near Alamosa
Magnitude
M 1.5 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Alamosa County, 27 km WSW
Nearest mapped fault
Northern Sangre de Cristo fault, 6 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1362 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 9 km (6 mi) from the epicentre. In Alamosa, 38 km away, the estimate is intensity I (not felt). 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 37.6353, -105.4888. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alamosa County, CO 27 km (17 mi) WSW earthquakes near Alamosa County
Costilla County, CO 40 km (25 mi) S earthquakes near Costilla County
Huerfano County, CO 47 km (29 mi) E earthquakes near Huerfano County
Custer County, CO 53 km (33 mi) N earthquakes near Custer County
Conejos County, CO 77 km (48 mi) SW earthquakes near Conejos County
Saguache County, CO 79 km (49 mi) NW earthquakes near Saguache County

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

Aftershocks so far

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

  1. 1.8 21 km WSW of Beulah Valley, Colorado
  2. 1.5 19 km NNE of Fort Garland, Colorado
  3. 1.6 6 km W of La Veta, Colorado
  4. 1.6 5 km WSW of La Veta, Colorado
  5. 1.6 3 km WNW of La Veta, Colorado
  6. 1.8 3 km W of La Veta, Colorado
  7. 1.5 3 km WNW of La Veta, Colorado
  8. 1.5 5 km NNW of La Veta, Colorado
  9. 2.1 3 km WNW of La Veta, Colorado
  10. 1.5 3 km W of La Veta, Colorado
  11. 2.4 2 km WNW of La Veta, Colorado
  12. 1.7 4 km W of La Veta, Colorado
  13. 1.5 20 km N of Blanca, Colorado
  14. 1.7 Colorado
  15. 1.5 26 km N of Fort Garland, 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.