QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Bozeman, MT

No earthquake was likely felt in Bozeman in the 24 hours to 12:24 pm MST (19:24 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 1.8 earthquake was recorded 32 km (20 mi) north-northwest of Bozeman, MT, at 2:47 pm MDT on 13 October 2020 (20:47 UTC), less than 1 km deep.

USGS: Western Montana

31 km (19 mi) NNW of Bozeman, MT

2:47 pm MDT, Oct 13, 2020 · · -1.4 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Gallatin County 47 kmBroadwater County 49 kmJefferson County 70 kmPark County 74 kmMeagher County 74 kmMadison County 89 kmSweet Grass County 98 kmSilver Bow County 114 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
2:47 pm MDT on 13 October 2020 ()
Where
32 km (20 mi) north-northwest of Bozeman, MT · earthquakes near Bozeman
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
-1.4 km below the surface
Felt
no reports yet
Nearest
Gallatin County, 47 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2219 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 13 km (8 mi) from the epicentre. In Bozeman, 32 km away, the estimate is intensity II (weak). 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.

Earthquakes near other towns within 30 km: Manhattan, Belgrade, Three Forks.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 4,600 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 · 29 km WNW of this epicentre
  2. 6.4 Clarkston Valley, Montana (Aftershock) · 29 km WNW of this epicentre
  3. 5.5 Clarkston Valley, Montana (Aftershock) · 29 km WNW of this epicentre
  4. 5.5 Clarkston Valley, Montana (Aftershock) · 29 km WNW of this epicentre
  5. 5.5 Clarkston Valley, Montana (Aftershock) · 29 km WNW 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 45.9447, -111.1913. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Gallatin County, MT 47 km (30 mi) S earthquakes near Gallatin County
Broadwater County, MT 49 km (30 mi) NNW earthquakes near Broadwater County
Jefferson County, MT 70 km (43 mi) WNW earthquakes near Jefferson County
Park County, MT 74 km (46 mi) SE earthquakes near Park County
Meagher County, MT 74 km (46 mi) NNE earthquakes near Meagher County
Madison County, MT 89 km (55 mi) SW earthquakes near Madison County

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

Aftershocks so far

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

  1. 2.4 4 km NNW of Logan, Montana
  2. 1.6 4 km NNW of Logan, Montana
  3. 1.5 2 km NNW of Logan, Montana
  4. 1.6 Western Montana
  5. 1.6 3 km WNW of Ponderosa Pines, Montana
  6. 1.6 9 km NNE of Three Forks, Montana
  7. 1.5 5 km NW of Logan, Montana
  8. 2.0 5 km NNE of Willow Creek, Montana
  9. 1.6 Western Montana
  10. 2.3 16 km SSW of Radersburg, Montana
  11. 1.6 15 km ESE of Harrison, Montana
  12. 2.2 2 km SE of Three Forks, Montana
  13. 1.6 5 km SW of Ponderosa Pines, Montana
  14. 2.2 5 km WSW of Ponderosa Pines, Montana
  15. 1.5 8 km ENE of Toston, 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.