QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6ml

10 km NNE of Black Eagle, Montana

· 19 km deep · released about 240 lb of TNT

10 km30 km60 km120 km N Cascade County 34 kmChouteau County 66 kmTeton County 82 kmJudith Basin County 94 kmPondera County 101 kmLewis and Clark County 103 kmLiberty County 106 kmMeagher County 116 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 2.6 (ml)
Depth
19 km below the surface
Felt
6 reports · strongest reported intensity III
Nearest
Cascade County, 34 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 9 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 6 people have reported feeling it to USGS.

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.

Where

Epicentre 47.6104, -111.2236. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Cascade County, MT 34 km (21 mi) NNE of here earthquakes near Cascade County
Chouteau County, MT 66 km (41 mi) WSW of here earthquakes near Chouteau County
Teton County, MT 82 km (51 mi) ESE of here earthquakes near Teton County
Judith Basin County, MT 94 km (59 mi) NW of here earthquakes near Judith Basin County
Pondera County, MT 101 km (63 mi) SE of here earthquakes near Pondera County
Lewis and Clark County, MT 103 km (64 mi) ENE of here earthquakes near Lewis and Clark County

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

Aftershocks so far

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

  1. 3.7 7 km NNW of Black Eagle, Montana
  2. 2.4 9 km NNE of Black Eagle, Montana
  3. 1.9 9 km N of Black Eagle, Montana

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 4.2 on 2026-01-29 — it released about 250 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.