QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

7 km ENE of Townsend, Montana

· 4.4 km deep · released about 6.2 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 6 kmMeagher County 47 kmJefferson County 54 kmGallatin County 93 kmSilver Bow County 107 kmCascade County 109 kmLewis and Clark County 114 kmJudith Basin County 115 kmMadison 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 1.5 (ml)
Depth
4.4 km below the surface
Felt
no reports yet
Nearest
Broadwater County, 6 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2049 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 6.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 46.3365, -111.4247. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 6 km (4 mi) E of here earthquakes near Broadwater County
Meagher County, MT 47 km (29 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 93 km (58 mi) NNW of here earthquakes near Gallatin County
Silver Bow County, MT 107 km (67 mi) ENE of here earthquakes near Silver Bow County
Cascade County, MT 109 km (68 mi) S of here earthquakes near Cascade 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. 1.8 8 km WSW of Townsend, Montana
  2. 1.9 8 km WSW of Townsend, Montana
  3. 3.1 6 km NNW of Three Forks, Montana
  4. 2.3 Western Montana
  5. 2.3 3 km NW of Three Forks, Montana
  6. 2.1 3 km NNW of Three Forks, Montana
  7. 2.0 3 km NNW of Three Forks, Montana
  8. 1.6 2 km WNW of Townsend, Montana
  9. 1.7 2 km NNW of Montana City, Montana
  10. 1.6 6 km NW of Ponderosa Pines, Montana
  11. 1.9 8 km WSW of Townsend, Montana
  12. 1.5 21 km NE of Townsend, Montana
  13. 1.9 9 km WSW of Townsend, Montana
  14. 2.4 4 km NNW of Logan, Montana
  15. 1.8 7 km WSW of Townsend, 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 9,800 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.