QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3mwr

Earthquake near Whitehall, MT

No earthquake was likely felt in Whitehall in the 24 hours to 2:42 pm MST (21:42 UTC). The last one was M 2.4, 21 km (13 mi) SW, at 3:27 am MDT on 25 October 2026, estimated intensity II (weak) in town. Every earthquake near Whitehall

This page: a magnitude 3.3 earthquake was recorded 18 km (11 mi) south of Whitehall, MT, at 10:56 pm MDT on 23 July 2018 (04:56 UTC), 10 km deep. 14 people have reported feeling it to USGS.

USGS: 17 km S of Whitehall, Montana

10:56 pm MDT, Jul 23, 2018 · · 10 km deep · released about 1.3 tons of TNT

Every earthquake near Whitehall Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Madison County 46 kmJefferson County 46 kmSilver Bow County 47 kmGallatin County 77 kmBroadwater County 84 kmBeaverhead County 88 kmDeer Lodge County 90 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
10:56 pm MDT on 23 July 2018 ()
Where
18 km (11 mi) south of Whitehall, MT · earthquakes near Whitehall
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 3.3 (mwr)
Depth
10 km below the surface
Felt
14 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Madison County, 46 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2955 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 51 km (32 mi) from the epicentre. In Whitehall, 18 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: Whitehall 18 km, intensity III · Butte 46 km, intensity II · Three Forks 48 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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 since 2016 was M 4.0 on 2016-09-03 — about 12 times the energy of this one.

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

  1. 5.4 Near Butte, Montana · 43 km NW 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 45.7115, -112.1210. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Madison County, MT 46 km (29 mi) SSE earthquakes near Madison County
Jefferson County, MT 46 km (29 mi) N earthquakes near Jefferson County
Silver Bow County, MT 47 km (29 mi) WNW earthquakes near Silver Bow County
Gallatin County, MT 77 km (48 mi) ESE earthquakes near Gallatin County
Broadwater County, MT 84 km (52 mi) NE earthquakes near Broadwater County
Beaverhead County, MT 88 km (55 mi) SW earthquakes near Beaverhead County

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

Aftershocks so far

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

  1. 1.6 5 km ENE of Butte, Montana
  2. 2.2 Western Montana
  3. 2.0 6 km ENE of Butte, Montana
  4. 1.7 4 km E of Butte, Montana
  5. 1.7 9 km S of Pony, Montana
  6. 1.6 5 km E of Butte, Montana
  7. 2.1 5 km E of Butte, Montana
  8. 1.9 11 km S of Pony, Montana
  9. 2.0 11 km S of Pony, Montana
  10. 1.7 4 km ENE of Butte, Montana
  11. 1.7 6 km E of Butte, Montana
  12. 1.7 4 km ENE of Butte, Montana
  13. 1.8 4 km E of Butte, Montana
  14. 1.6 5 km ENE of Butte, Montana
  15. 1.7 4 km ENE of Butte, 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.