QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

8 km NE 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 14 kmMeagher County 52 kmJefferson County 54 kmGallatin County 81 kmSilver Bow County 106 kmPark County 108 kmMadison County 109 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
1 report · strongest reported intensity II
Nearest
Broadwater County, 14 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2412 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has 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 46.2330, -111.3764. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 14 km (9 mi) SE of here earthquakes near Broadwater County
Meagher County, MT 52 km (33 mi) SW of here earthquakes near Meagher County
Jefferson County, MT 54 km (34 mi) ENE of here earthquakes near Jefferson County
Gallatin County, MT 81 km (50 mi) NNW of here earthquakes near Gallatin County
Silver Bow County, MT 106 km (66 mi) ENE of here earthquakes near Silver Bow County
Park County, MT 108 km (67 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. 1.6 4 km NNW of Logan, Montana
  2. 1.8 Western Montana
  3. 2.4 2 km SW of Ponderosa Pines, Montana
  4. 2.0 11 km SSW of Radersburg, Montana
  5. 1.6 2 km ENE of Manhattan, Montana
  6. 1.6 6 km WSW of Townsend, Montana
  7. 2.0 3 km WNW of Manhattan, Montana
  8. 2.3 2 km W of Manhattan, Montana
  9. 1.7 8 km S of Ponderosa Pines, Montana
  10. 1.6 6 km W of Townsend, Montana
  11. 1.8 4 km S of Radersburg, Montana
  12. 2.1 6 km ENE of Toston, Montana
  13. 1.7 5 km W of Townsend, Montana
  14. 1.5 4 km WNW of Townsend, Montana
  15. 1.5 11 km NE of Manhattan, 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.