QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Bozeman, MT

No earthquake was likely felt in Bozeman in the 24 hours to 2:50 pm MST (21:50 UTC). The last one was M 3.0, 17 km (10 mi) NW, at 7:42 am MDT on 1 June 2024, estimated intensity II (weak) in town; 20 felt reports to USGS. Every earthquake near Bozeman

This page: a magnitude 1.6 earthquake was recorded 36 km (23 mi) west-northwest of Bozeman, MT, at 2:39 pm MST on 6 December 2021 (21:39 UTC), 4.2 km deep.

USGS: 3 km S of Logan, Montana

35 km (22 mi) WNW of Bozeman, MT

2:39 pm MST, Dec 6, 2021 · · 4.2 km deep · released about 9 lb of TNT

Every earthquake near Bozeman Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Gallatin County 43 kmBroadwater County 53 kmJefferson County 57 kmMadison County 70 kmPark County 82 kmMeagher County 90 kmSilver Bow County 95 kmSweet Grass County 115 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
2:39 pm MST on 6 December 2021 ()
Where
36 km (23 mi) west-northwest of Bozeman, MT · earthquakes near Bozeman
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.6 (ml)
Depth
4.2 km below the surface
Felt
no reports yet
Nearest
Gallatin County, 43 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1801 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. In Bozeman, 36 km away, the estimate is intensity I (not felt). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Manhattan 8 km, intensity II · Three Forks 10 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 9 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.2 on 2019-08-16 — about 6,700 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 The 1925 Clarkston Valley, Montana Earthquake · 26 km NNW of this epicentre
  2. 6.4 Clarkston Valley, Montana (Aftershock) · 26 km NNW of this epicentre
  3. 5.5 Clarkston Valley, Montana (Aftershock) · 26 km NNW of this epicentre
  4. 5.5 Clarkston Valley, Montana (Aftershock) · 26 km NNW of this epicentre
  5. 5.5 Clarkston Valley, Montana (Aftershock) · 26 km NNW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 45.8532, -111.4343. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Gallatin County, MT 43 km (27 mi) SSE earthquakes near Gallatin County
Broadwater County, MT 53 km (33 mi) N earthquakes near Broadwater County
Jefferson County, MT 57 km (35 mi) WNW earthquakes near Jefferson County
Madison County, MT 70 km (43 mi) SSW earthquakes near Madison County
Park County, MT 82 km (51 mi) ESE earthquakes near Park County
Meagher County, MT 90 km (56 mi) NNE earthquakes near Meagher County

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

Aftershocks so far

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

  1. 2.0 5 km NNW of Logan, Montana
  2. 1.7 0 km SW of Three Forks, Montana
  3. 1.6 5 km SSW of Willow Creek, Montana
  4. 2.1 3 km WNW of Pony, Montana
  5. 1.8 5 km NNW of Logan, Montana
  6. 1.5 Western Montana
  7. 2.0 3 km WNW of Pony, Montana
  8. 1.8 18 km N of Ennis, Montana
  9. 2.5 3 km WNW of Pony, Montana
  10. 1.6 Western Montana
  11. 1.7 16 km N of Big Sky, Montana
  12. 1.6 3 km WSW of Ponderosa Pines, Montana
  13. 1.6 14 km ESE of Harrison, Montana
  14. 2.1 17 km NNE of Ennis, Montana
  15. 1.5 10 km WNW of Four Corners, 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.