QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

11 km ENE of Toston, Montana

· 4.1 km deep · released about 72 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 19 kmMeagher County 51 kmJefferson County 58 kmGallatin County 79 kmPark County 103 kmMadison County 110 kmSilver Bow County 110 kmSweet Grass County 115 kmWheatland 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 2.3 (ml)
Depth
4.1 km below the surface
Felt
no reports yet
Nearest
Broadwater County, 19 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2290 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 72 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 210,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 150,000× the energy of this one
  3. Around the size people start to feel M 3.0 13× the energy of this one
  4. This earthquake M 2.3 about 72 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 46.2188, -111.3128. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 19 km (12 mi) SE of here earthquakes near Broadwater County
Meagher County, MT 51 km (31 mi) SW of here earthquakes near Meagher County
Jefferson County, MT 58 km (36 mi) E of here earthquakes near Jefferson County
Gallatin County, MT 79 km (49 mi) N of here earthquakes near Gallatin County
Park County, MT 103 km (64 mi) NW of here earthquakes near Park County
Madison County, MT 110 km (68 mi) NNE of here earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.7 8 km WSW of Townsend, Montana
  2. 1.6 7 km W of Townsend, Montana
  3. 2.3 16 km SSW of Radersburg, Montana
  4. 1.5 6 km W of Townsend, Montana
  5. 1.7 8 km WSW of Townsend, Montana
  6. 1.6 8 km WSW of Townsend, Montana
  7. 2.2 2 km SE of Three Forks, Montana
  8. 1.6 5 km SW of Ponderosa Pines, Montana
  9. 2.2 5 km WSW of Ponderosa Pines, Montana
  10. 1.5 8 km ENE of Toston, Montana
  11. 1.5 6 km SSW of The Silos, Montana
  12. 1.5 7 km W of Townsend, Montana
  13. 1.6 7 km WSW of Townsend, Montana
  14. 1.9 14 km SW of Radersburg, Montana
  15. 1.9 14 km SW of Radersburg, 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 2019-08-16 — it released about 840 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.