QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Springfield, CO

No earthquake was likely felt in Springfield in the 24 hours to 2:48 pm MST (21:48 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 1.6 earthquake was recorded 29 km (18 mi) west of Springfield, CO, at 5:26 am MDT on 15 September 2021 (11:26 UTC), 10 km deep.

USGS: 10 km NW of Pritchett, Colorado

5:26 am MDT, Sep 15, 2021 · · 10 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N Baca County 38 kmBent County 56 kmProwers County 75 kmOtero County 84 kmCimarron County 86 kmLas Animas County 98 kmStanton County 103 kmMorton County 104 kmKiowa 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
5:26 am MDT on 15 September 2021 ()
Where
29 km (18 mi) west of Springfield, CO · earthquakes near Springfield
Magnitude
M 1.6 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Baca County, 38 km ESE
Status
Reviewed by a seismologist

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

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Springfield, 29 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 37.4439, -102.9413. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Baca County, CO 38 km (24 mi) ESE earthquakes near Baca County
Bent County, CO 56 km (35 mi) NNW earthquakes near Bent County
Prowers County, CO 75 km (47 mi) NE earthquakes near Prowers County
Otero County, CO 84 km (52 mi) NW earthquakes near Otero County
Cimarron County, OK 86 km (53 mi) SSE earthquakes near Cimarron County
Las Animas County, CO 98 km (61 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

4 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

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.