QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

28 km WSW of Augusta, Montana

· 15 km deep · released about 21 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 45 kmTeton County 56 kmPowell County 67 kmMissoula County 97 kmPondera County 97 kmLake County 102 kmCascade County 107 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 1.9 (ml)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Lewis and Clark County, 45 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 910 days ago

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

How big was it?

This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. This earthquake M 1.9 about 21 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 47.4342, -112.7595. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 45 km (28 mi) NW of here earthquakes near Lewis and Clark County
Teton County, MT 56 km (35 mi) SW of here earthquakes near Teton County
Powell County, MT 67 km (42 mi) N of here earthquakes near Powell County
Missoula County, MT 97 km (60 mi) ENE of here earthquakes near Missoula County
Pondera County, MT 97 km (60 mi) SSW of here earthquakes near Pondera County
Lake County, MT 102 km (63 mi) ESE of here earthquakes near Lake County

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

Aftershocks so far

30 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. 2.4 16 km ENE of Seeley Lake, Montana
  15. 3.0 26 km WSW of Augusta, 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.