QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

11 km NE of Townsend, Montana

· 8.7 km deep · released about 69 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 10 kmMeagher County 43 kmJefferson County 58 kmGallatin County 100 kmCascade County 103 kmLewis and Clark County 109 kmJudith Basin County 110 kmSilver Bow County 111 kmWheatland County 120 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 2.2 (ml)
Depth
8.7 km below the surface
Felt
no reports yet
Nearest
Broadwater County, 10 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1569 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 69 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 220,000× 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 14× the energy of this one
  4. This earthquake M 2.2 about 69 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 46.3957, -111.4170. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 10 km (6 mi) NE of here earthquakes near Broadwater County
Meagher County, MT 43 km (27 mi) WSW of here earthquakes near Meagher County
Jefferson County, MT 58 km (36 mi) ENE of here earthquakes near Jefferson County
Gallatin County, MT 100 km (62 mi) N of here earthquakes near Gallatin County
Cascade County, MT 103 km (64 mi) S of here earthquakes near Cascade County
Lewis and Clark County, MT 109 km (68 mi) SE 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

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

  1. 2.4 10 km E of Toston, Montana
  2. 2.9 28 km ENE of Helena Valley Northeast, Montana
  3. 2.7 28 km ENE of Helena Valley Northeast, Montana
  4. 2.1 29 km ENE of Helena Valley Northeast, Montana
  5. 1.8 8 km S of Ponderosa Pines, Montana
  6. 2.1 8 km S of Ponderosa Pines, Montana
  7. 2.9 6 km S of Ponderosa Pines, Montana
  8. 1.6 7 km SSW of The Silos, Montana
  9. 1.7 7 km SSW of The Silos, Montana
  10. 1.9 8 km WSW of Townsend, Montana
  11. 2.2 1 km NW of East Helena, Montana
  12. 1.5 10 km NNE of Three Forks, Montana
  13. 1.8 4 km WNW of Ponderosa Pines, Montana
  14. 1.6 8 km W of Townsend, Montana
  15. 2.2 11 km S 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.

On USGS

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