QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

5 km N of Craig, Montana

· 6.2 km deep · released about 170 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 33 kmCascade County 50 kmPowell County 81 kmTeton County 81 kmBroadwater County 95 kmMeagher County 99 kmJefferson County 112 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 2.5 (ml)
Depth
6.2 km below the surface
Felt
6 reports · strongest reported intensity IV
Nearest
Lewis and Clark County, 33 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 631 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 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 47.1259, -111.9517. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 33 km (20 mi) E of here earthquakes near Lewis and Clark County
Cascade County, MT 50 km (31 mi) WSW of here earthquakes near Cascade County
Powell County, MT 81 km (50 mi) ENE of here earthquakes near Powell County
Teton County, MT 81 km (50 mi) SSE of here earthquakes near Teton County
Broadwater County, MT 95 km (59 mi) NNW of here earthquakes near Broadwater County
Meagher County, MT 99 km (61 mi) NW of here earthquakes near Meagher County

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

Aftershocks so far

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

  1. 1.5 16 km NE of Helena Valley Northwest, Montana
  2. 1.6 14 km SSE of Craig, Montana
  3. 2.4 21 km SSE of Craig, Montana
  4. 2.0 32 km ENE of Helena Valley Northeast, Montana
  5. 2.0 20 km NNE of Helena Valley Northeast, Montana
  6. 1.5 31 km ENE of Helena Valley Northeast, Montana
  7. 2.0 19 km E of Lincoln, Montana
  8. 1.5 17 km E of Lincoln, Montana
  9. 1.6 18 km E of Lincoln, Montana
  10. 1.6 6 km SE of Craig, Montana
  11. 2.1 15 km E of Lincoln, Montana
  12. 2.5 23 km SSE of Craig, Montana
  13. 1.9 23 km SSE of Craig, Montana
  14. 2.1 22 km NNE of Helena Valley Northeast, Montana
  15. 1.6 19 km E of Lincoln, 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 4.3 on 2016-01-30 — it released about 560 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.