QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Great Falls, MT

No earthquake was likely felt in Great Falls in the 24 hours to 3:35 am MST (10:35 UTC). The last one was M 3.7, 9 km (6 mi) NNW, at 7:40 am MDT on 18 September 2026, estimated intensity III (weak) in town; 176 felt reports to USGS. Every earthquake near Great Falls

This page: a magnitude 1.6 earthquake was recorded 41 km (26 mi) northeast of Great Falls, MT, at 8:13 am MDT on 9 May 2024 (14:13 UTC), 6.1 km deep.

USGS: 4 km ESE of Carter, Montana

41 km (26 mi) NE of Great Falls, MT

8:13 am MDT, May 9, 2024 · · 6.1 km deep · released about 6.6 lb of TNT

10 km30 km60 km120 km N Chouteau County 38 kmCascade County 59 kmLiberty County 90 kmJudith Basin County 93 kmTeton County 103 kmPondera County 111 kmHill County 114 kmToole County 116 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
8:13 am MDT on 9 May 2024 ()
Where
41 km (26 mi) northeast of Great Falls, MT · earthquakes near Great Falls
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.6 (ml)
Depth
6.1 km below the surface
Felt
no reports yet
Nearest
Chouteau County, 38 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 916 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 9 km (6 mi) from the epicentre. In Great Falls, 41 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.

Earthquakes near other towns within 30 km: Fort Benton.

How big was it?

This earthquake released about 6.6 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 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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 47.7592, -110.9055. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chouteau County, MT 38 km (23 mi) ENE earthquakes near Chouteau County
Cascade County, MT 59 km (37 mi) SW earthquakes near Cascade County
Liberty County, MT 90 km (56 mi) N earthquakes near Liberty County
Judith Basin County, MT 93 km (58 mi) SSE earthquakes near Judith Basin County
Teton County, MT 103 km (64 mi) W earthquakes near Teton County
Pondera County, MT 111 km (69 mi) WNW earthquakes near Pondera County

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

Aftershocks so far

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

  1. 3.7 7 km NNW of Black Eagle, Montana
  2. 2.4 9 km NNE of Black Eagle, Montana
  3. 1.9 9 km N of Black Eagle, Montana
  4. 2.6 10 km NNE of Black Eagle, Montana
  5. 3.7 3 km SE of Black Eagle, Montana
  6. 3.2 3 km NW of Malmstrom Air Force Base, Montana
  7. 2.7 5 km NNW of Malmstrom Air Force Base, Montana
  8. 4.2 9 km N of Black Eagle, 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.