QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Three Forks, MT

No earthquake was likely felt in Three Forks in the 24 hours to 1:39 am MST (08:39 UTC). The last one was M 1.6, 7 km (5 mi) NE, at 4:03 pm MDT on 11 August 2026, estimated intensity II (weak) in town. Every earthquake near Three Forks

This page: a magnitude 1.8 earthquake was recorded 11 km (7 mi) north-northeast of Three Forks, MT, at 11:37 pm MST on 25 February 2019 (06:37 UTC), 12 km deep.

USGS: 11 km NNE of Three Forks, Montana

49 km (30 mi) NW of Bozeman, MT

11:37 pm MST, Feb 25, 2019 · · 12 km deep · released about 15 lb of TNT

Every earthquake near Three Forks Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 38 kmJefferson County 45 kmGallatin County 59 kmMeagher County 80 kmMadison County 80 kmSilver Bow County 90 kmPark County 96 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
11:37 pm MST on 25 February 2019 ()
Where
11 km (7 mi) north-northeast of Three Forks, MT · earthquakes near Three Forks
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Broadwater County, 38 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2817 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 6 km (4 mi) from the epicentre. In Three Forks, 11 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.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 The 1925 Clarkston Valley, Montana Earthquake · 10 km N of this epicentre
  2. 6.4 Clarkston Valley, Montana (Aftershock) · 10 km N of this epicentre
  3. 5.5 Clarkston Valley, Montana (Aftershock) · 10 km N of this epicentre
  4. 5.5 Clarkston Valley, Montana (Aftershock) · 10 km N of this epicentre
  5. 5.5 Clarkston Valley, Montana (Aftershock) · 10 km N 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 45.9907, -111.5073. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Broadwater County, MT 38 km (23 mi) N earthquakes near Broadwater County
Jefferson County, MT 45 km (28 mi) WNW earthquakes near Jefferson County
Gallatin County, MT 59 km (37 mi) SSE earthquakes near Gallatin County
Meagher County, MT 80 km (50 mi) NE earthquakes near Meagher County
Madison County, MT 80 km (50 mi) SSW earthquakes near Madison County
Silver Bow County, MT 90 km (56 mi) W earthquakes near Silver Bow 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. 1.6 7 km SSW of The Silos, Montana
  2. 1.7 3 km WNW of Manhattan, Montana
  3. 1.6 4 km N of Logan, Montana
  4. 2.0 11 km W of Sedan, Montana
  5. 2.4 2 km WNW of Manhattan, Montana
  6. 1.5 1 km WNW of Manhattan, Montana
  7. 1.7 1 km W of Manhattan, Montana
  8. 1.6 2 km WNW of Manhattan, Montana
  9. 2.3 2 km WNW of Manhattan, Montana
  10. 1.7 2 km WNW of Manhattan, Montana
  11. 1.8 6 km SSW of The Silos, Montana
  12. 2.4 1 km WNW of Manhattan, Montana
  13. 1.6 3 km WNW of Manhattan, Montana
  14. 2.7 2 km WNW of Manhattan, Montana
  15. 1.5 9 km SSW of Elkhorn, 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.