QuakeIndex

Earthquake · reviewed by a seismologist

M 4.1mwr

Earthquake near Dillon, MT

No earthquake was likely felt in Dillon in the 24 hours to 5:28 am MST (12:28 UTC). The last one was M 2.0, 14 km (9 mi) N, at 2:45 pm MDT on 7 May 2026, estimated intensity II (weak) in town. Every earthquake near Dillon

This page: a magnitude 4.1 earthquake was recorded 12 km (7 mi) east of Dillon, MT, at 12:54 am MDT on 7 October 2024 (06:54 UTC), 17 km deep. 225 people have reported feeling it to USGS.

USGS: 11 km E of Dillon, Montana

12:54 am MDT, Oct 7, 2024 · · 17 km deep · released about 21 tons of TNT

10 km30 km60 km120 km N Beaverhead County 33 kmMadison County 46 kmSilver Bow County 76 kmClark County 105 kmJefferson County 105 kmGallatin County 108 kmDeer Lodge County 109 kmLemhi 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
12:54 am MDT on 7 October 2024 ()
Where
12 km (7 mi) east of Dillon, MT · earthquakes near Dillon
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 4.1 (mwr)
Depth
17 km below the surface
Felt
225 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Beaverhead County, 33 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 50 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 103 km (64 mi) from the epicentre. In Dillon, 12 km away, the estimate is intensity III (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.

Likely felt in: Dillon 12 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 21 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 7,900× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 350× the energy of this one
  3. Magna, Utah 2020 M 5.7 250× the energy of this one
  4. This earthquake M 4.1 about 21 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 45× more

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 (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.6 16 km N of Dillon, Montana · 18 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 45.2265, -112.4871. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Beaverhead County, MT 33 km (21 mi) WSW earthquakes near Beaverhead County
Madison County, MT 46 km (29 mi) ENE earthquakes near Madison County
Silver Bow County, MT 76 km (47 mi) N earthquakes near Silver Bow County
Clark County, ID 105 km (65 mi) S earthquakes near Clark County
Jefferson County, MT 105 km (65 mi) NNE earthquakes near Jefferson County
Gallatin County, MT 108 km (67 mi) ENE earthquakes near Gallatin County

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

Aftershocks so far

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

  1. 1.4 19 km N of Dillon, Montana
  2. 1.0 11 km WSW of Sheridan, Montana
  3. 2.1 15 km ENE of Twin Bridges, Montana
  4. 1.9 19 km NNE of Dillon, Montana
  5. 2.0 15 km NNE of Dillon, Montana
  6. 2.1 26 km SE of Dillon, Montana
  7. 2.0 13 km N of Dillon, Montana
  8. 1.6 11 km NNE of Dillon, Montana
  9. 2.5 9 km NNE of Dillon, Montana
  10. 1.5 14 km NNE of Dillon, Montana
  11. 2.5 10 km NNE of Dillon, Montana
  12. 1.8 27 km SW of Dillon, Montana
  13. 1.6 16 km SSW of Dillon, Montana
  14. 1.5 12 km N of Dillon, Montana
  15. 1.7 17 km NNE of Dillon, 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.