QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6mb_lg

Earthquake near Chadron, NE

No earthquake was likely felt in Chadron in the 24 hours to 6:55 pm MST (01:55 UTC). The last one was M 3.6, 97 km (60 mi) NNW, at 8:14 pm MST on 8 March 2025, estimated intensity II (weak) in town; 7 felt reports to USGS. Every earthquake near Chadron

This page: a magnitude 2.6 earthquake was recorded 48 km (30 mi) west-southwest of Chadron, NE, at 12:16 pm MST on 27 February 2021 (19:16 UTC), 5.0 km deep.

USGS: 13 km WNW of Crawford, Nebraska

12:16 pm MST, Feb 27, 2021 · · 5.0 km deep · released about 240 lb of TNT

10 km30 km60 km120 km N Sioux County 30 kmDawes County 35 kmFall River County 57 kmBox Butte County 68 kmNiobrara County 83 kmGoshen County 94 kmScotts Bluff County 96 kmSheridan County 101 kmOglala Lakota County 107 km
Distance rings around the epicentre, with the nearest towns at their true direction. Not a shaking map — see the USGS ShakeMap for that.
When
12:16 pm MST on 27 February 2021 ()
Where
48 km (30 mi) west-southwest of Chadron, NE · earthquakes near Chadron
Magnitude
M 2.6 (mb_lg)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Sioux County, 30 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2008 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 51 km (32 mi) from the epicentre. In Chadron, 48 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 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
  3. Around the size people start to feel M 3.0 4× the energy of this one
  4. This earthquake M 2.6 about 240 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 42.7092, -103.5676. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sioux County, NE 30 km (18 mi) SSW earthquakes near Sioux County
Dawes County, NE 35 km (22 mi) E earthquakes near Dawes County
Fall River County, SD 57 km (36 mi) N earthquakes near Fall River County
Box Butte County, NE 68 km (42 mi) SE earthquakes near Box Butte County
Niobrara County, WY 83 km (52 mi) WNW earthquakes near Niobrara County
Goshen County, WY 94 km (59 mi) SW earthquakes near Goshen County

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

Aftershocks so far

No further earthquakes have been recorded within 50 km since this one.

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.