QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mwr

5 km N of Sequndo, Colorado

· 4.5 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Huerfano County 61 kmColfax County 62 kmLas Animas County 63 kmCostilla County 63 kmAlamosa County 104 kmTaos County 104 kmPueblo County 112 kmCuster County 118 kmOtero County 119 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
Magnitude
M 3.9 (mwr)
Depth
4.5 km below the surface
Felt
14 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Huerfano County, 61 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 718 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 14 people have reported feeling it to USGS.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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.

Where

Epicentre 37.1696, -104.7283. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Huerfano County, CO 61 km (38 mi) SSE of here earthquakes near Huerfano County
Colfax County, NM 62 km (39 mi) N of here earthquakes near Colfax County
Las Animas County, CO 63 km (39 mi) WSW of here earthquakes near Las Animas County
Costilla County, CO 63 km (39 mi) E of here earthquakes near Costilla County
Alamosa County, CO 104 km (64 mi) ESE of here earthquakes near Alamosa County
Taos County, NM 104 km (65 mi) NE of here earthquakes near Taos County

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

Aftershocks so far

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

  1. 3.2 6 km NW of El Moro, Colorado
  2. 2.3 7 km N of El Moro, Colorado
  3. 2.1 10 km SW of Weston, Colorado
  4. 1.6 13 km SW of Weston, Colorado
  5. 1.9 New Mexico
  6. 2.6 16 km SSW of Weston, Colorado
  7. 1.5 New Mexico
  8. 2.1 7 km WNW of Hoehne, Colorado
  9. 1.5 10 km NNE of Weston, Colorado
  10. 1.7 31 km S of Segundo, Colorado
  11. 2.8 18 km S of Stonewall Gap, Colorado
  12. 3.1 15 km SW of Weston, Colorado
  13. 2.5 7 km N of El Moro, Colorado
  14. 2.3 8 km N of Segundo, Colorado
  15. 1.7 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.3 on 2023-03-10 — it released about 4 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.