QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

Earthquake near Rocky Ford, CO

No earthquake was likely felt in Rocky Ford in the 24 hours to 7:10 am MST (14:10 UTC). The last one was M 3.4, 156 km (97 mi) SW, at 3:34 am MST on 8 November 2026, estimated intensity II (weak) in town; 2 felt reports to USGS. Every earthquake near Rocky Ford

This page: a magnitude 2.3 earthquake was recorded 18 km (11 mi) west of Rocky Ford, CO, at 3:50 pm MDT on 18 September 2020 (21:50 UTC), 5.0 km deep.

USGS: 10 km SSW of Manzanola, Colorado

3:50 pm MDT, Sep 18, 2020 · · 5.0 km deep · released about 85 lb of TNT

10 km30 km60 km120 km N Otero County 24 kmCrowley County 34 kmPueblo County 52 kmBent County 75 kmLas Animas County 79 kmHuerfano County 99 kmEl Paso County 104 kmKiowa County 109 kmLincoln County 113 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
3:50 pm MDT on 18 September 2020 ()
Where
18 km (11 mi) west of Rocky Ford, CO · earthquakes near Rocky Ford
Magnitude
M 2.3 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Otero County, 24 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2174 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 37 km (23 mi) from the epicentre. In Rocky Ford, 18 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.

Earthquakes near other towns within 30 km: Fowler, Ordway.

How big was it?

This earthquake released about 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 85 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 38.0265, -103.9208. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Otero County, CO 24 km (15 mi) SE earthquakes near Otero County
Crowley County, CO 34 km (21 mi) NNE earthquakes near Crowley County
Pueblo County, CO 52 km (32 mi) WNW earthquakes near Pueblo County
Bent County, CO 75 km (46 mi) E earthquakes near Bent County
Las Animas County, CO 79 km (49 mi) S earthquakes near Las Animas County
Huerfano County, CO 99 km (61 mi) WSW earthquakes near Huerfano County

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

Aftershocks so far

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

  1. 1.7 16 km NNW of Olney Springs, Colorado
  2. 1.8 11 km ESE of Boone, Colorado
  3. 1.8 11 km SSW of Fowler, Colorado
  4. 1.8 6 km WSW of Fowler, 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.