QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Belgrade, MT

No earthquake was likely felt in Belgrade in the 24 hours to 9:49 am MST (16:49 UTC). The last one was M 1.6, 8 km (5 mi) WSW, at 4:23 pm MDT on 28 September 2025, estimated intensity II (weak) in town. Every earthquake near Belgrade

This page: a magnitude 1.6 earthquake was recorded 48 km (30 mi) west-southwest of Belgrade, MT, at 9:43 am MDT on 16 May 2020 (15:43 UTC), 1.4 km deep.

USGS: 9 km SSE of Harrison, Montana

55 km (34 mi) W of Bozeman, MT

9:43 am MDT, May 16, 2020 · · 1.4 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N Madison County 35 kmGallatin County 47 kmJefferson County 61 kmSilver Bow County 77 kmBroadwater County 82 kmPark County 96 kmBeaverhead County 104 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
9:43 am MDT on 16 May 2020 ()
Where
48 km (30 mi) west-southwest of Belgrade, MT · earthquakes near Belgrade
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.6 (ml)
Depth
1.4 km below the surface
Felt
no reports yet
Nearest
Madison County, 35 km SSW
Nearest mapped fault
Madison fault, 22 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2369 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 Belgrade, 48 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.

How big was it?

This earthquake released about 7.3 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 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 8,200 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 45.6178, -111.7490. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Madison County, MT 35 km (22 mi) SSW earthquakes near Madison County
Gallatin County, MT 47 km (29 mi) ESE earthquakes near Gallatin County
Jefferson County, MT 61 km (38 mi) NNW earthquakes near Jefferson County
Silver Bow County, MT 77 km (48 mi) WNW earthquakes near Silver Bow County
Broadwater County, MT 82 km (51 mi) NNE earthquakes near Broadwater County
Park County, MT 96 km (60 mi) E earthquakes near Park County

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

Aftershocks so far

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

  1. 1.7 10 km SSE of Pony, Montana
  2. 2.0 9 km SSE of Pony, Montana
  3. 2.7 9 km SSE of Pony, Montana
  4. 1.6 9 km NNE of Three Forks, Montana
  5. 1.5 5 km NW of Logan, Montana
  6. 2.0 5 km NNE of Willow Creek, Montana
  7. 2.0 3 km W of Pony, Montana
  8. 1.9 12 km NNW of Ennis, Montana
  9. 2.2 12 km NNW of Ennis, Montana
  10. 1.6 15 km ESE of Harrison, Montana
  11. 1.8 2 km N of Pony, Montana
  12. 1.5 7 km NNE of Big Sky, Montana
  13. 2.2 2 km SE of Three Forks, Montana
  14. 1.6 5 km SW of Ponderosa Pines, Montana
  15. 1.6 17 km W of Pony, 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.