QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

26 km WSW of Augusta, Montana

· 31 km deep · released about 340 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 42 kmTeton County 55 kmPowell County 67 kmPondera County 97 kmMissoula County 99 kmCascade County 104 kmLake County 105 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 2.7 (ml)
Depth
31 km below the surface
Felt
no reports yet
Nearest
Lewis and Clark County, 42 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1554 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 47.4261, -112.7230. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 42 km (26 mi) NW of here earthquakes near Lewis and Clark County
Teton County, MT 55 km (34 mi) SW of here earthquakes near Teton County
Powell County, MT 67 km (41 mi) NNE of here earthquakes near Powell County
Pondera County, MT 97 km (60 mi) SSW of here earthquakes near Pondera County
Missoula County, MT 99 km (61 mi) ENE of here earthquakes near Missoula County
Cascade County, MT 104 km (65 mi) W of here earthquakes near Cascade County

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

Aftershocks so far

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

  1. 2.4 32 km ENE of Seeley Lake, Montana
  2. 2.6 31 km ENE of Seeley Lake, Montana
  3. 2.1 25 km ENE of Seeley Lake, Montana
  4. 1.8 20 km N of Lincoln, Montana
  5. 3.1 27 km NE of Seeley Lake, Montana
  6. 1.5 40 km NE of Seeley Lake, Montana
  7. 2.2 40 km NE of Seeley Lake, Montana
  8. 1.6 40 km ENE of Condon, Montana
  9. 1.5 26 km W of Augusta, Montana
  10. 2.3 34 km NE of Seeley Lake, Montana
  11. 1.8 20 km N of Ovando, Montana
  12. 2.2 43 km NNE of Ovando, Montana
  13. 2.5 42 km NNE of Ovando, Montana
  14. 3.0 26 km WSW of Augusta, Montana
  15. 1.6 15 km WNW 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.