QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7mwr

Earthquake near Springfield, CO

No earthquake was likely felt in Springfield in the 24 hours to 7:42 am MST (14:42 UTC). The last one was M 3.4, 213 km (133 mi) W, at 3:34 am MST on 8 November 2026, estimated intensity II (weak) in town; 2 felt reports to USGS. Every earthquake near Springfield

This page: a magnitude 3.7 earthquake was recorded 28 km (17 mi) west of Springfield, CO, at 3:27 am MDT on 13 September 2021 (09:27 UTC), 16 km deep. 39 people have reported feeling it to USGS.

USGS: 9 km NW of Pritchett, Colorado

3:27 am MDT, Sep 13, 2021 · · 16 km deep · released about 5.4 tons of TNT

10 km30 km60 km120 km N Baca County 36 kmBent County 57 kmProwers County 75 kmCimarron County 84 kmOtero County 86 kmLas Animas County 100 kmStanton County 101 kmMorton County 102 kmKiowa County 107 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
3:27 am MDT on 13 September 2021 ()
Where
28 km (17 mi) west of Springfield, CO · earthquakes near Springfield
Magnitude
M 3.7 (mwr)
Depth
16 km below the surface
Felt
39 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Baca County, 36 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1814 days ago

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 370 km (230 mi) from the epicentre. In Springfield, 28 km away, the estimate is intensity III (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 5.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 32,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,000× the energy of this one
  4. This earthquake M 3.7 about 5.4 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 11× 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.

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 37.4346, -102.9250. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Baca County, CO 36 km (23 mi) ESE earthquakes near Baca County
Bent County, CO 57 km (35 mi) NNW earthquakes near Bent County
Prowers County, CO 75 km (46 mi) NE earthquakes near Prowers County
Cimarron County, OK 84 km (52 mi) SSE earthquakes near Cimarron County
Otero County, CO 86 km (53 mi) NW earthquakes near Otero County
Las Animas County, CO 100 km (62 mi) W earthquakes near Las Animas County

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

Aftershocks so far

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

  1. 1.8 25 km E of Kim, Colorado
  2. 2.2 32 km NW of Two Buttes, Colorado
  3. 1.9 20 km NNW of Kenton, Oklahoma
  4. 1.9 23 km W of Pritchett, Colorado
  5. 1.6 10 km NW of Pritchett, 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.