QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

10 km NNE of Toston, Montana

· 5.0 km deep · released about 170 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 13 kmMeagher County 50 kmJefferson County 55 kmGallatin County 83 kmSilver Bow County 107 kmPark County 109 kmMadison County 112 kmCascade County 118 kmJudith Basin County 119 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
5.0 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Broadwater County, 13 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2360 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 3 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 46.2547, -111.3709. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 13 km (8 mi) SE of here earthquakes near Broadwater County
Meagher County, MT 50 km (31 mi) SW of here earthquakes near Meagher County
Jefferson County, MT 55 km (34 mi) ENE of here earthquakes near Jefferson County
Gallatin County, MT 83 km (52 mi) N of here earthquakes near Gallatin County
Silver Bow County, MT 107 km (67 mi) ENE of here earthquakes near Silver Bow County
Park County, MT 109 km (68 mi) NW of here earthquakes near Park County

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

Aftershocks so far

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

  1. 2.1 1 km SSE of Townsend, Montana
  2. 1.6 6 km N of Radersburg, Montana
  3. 1.5 7 km ENE of Townsend, Montana
  4. 1.6 8 km ENE of Townsend, Montana
  5. 1.8 7 km W of Townsend, Montana
  6. 2.2 6 km NNE of Manhattan, Montana
  7. 1.9 7 km SW of Radersburg, Montana
  8. 1.7 7 km SW of Radersburg, Montana
  9. 1.6 5 km NE of Logan, Montana
  10. 1.5 22 km SW of Radersburg, Montana
  11. 1.7 10 km WSW of Townsend, Montana
  12. 1.6 8 km WSW of Townsend, Montana
  13. 2.1 6 km NNE of Manhattan, Montana
  14. 2.0 4 km N of Logan, Montana
  15. 1.6 4 km NNW of Logan, 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 350 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.