QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

Earthquake near Whitehall, MT

No earthquake was likely felt in Whitehall in the 24 hours to 11:33 pm MST (06:33 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 2.7 earthquake was recorded 20 km (12 mi) southeast of Whitehall, MT, at 1:46 pm MDT on 23 March 2018 (19:46 UTC), 11 km deep. 1 person has reported feeling it to USGS.

USGS: 11 km NW of Harrison, Montana

1:46 pm MDT, Mar 23, 2018 · · 11 km deep · released about 340 lb of TNT

Every earthquake near Whitehall Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 41 kmMadison County 50 kmSilver Bow County 62 kmGallatin County 63 kmBroadwater County 69 kmDeer Lodge County 104 kmBeaverhead County 106 kmPark County 111 kmMeagher County 117 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
1:46 pm MDT on 23 March 2018 ()
Where
20 km (12 mi) southeast of Whitehall, MT · earthquakes near Whitehall
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 2.7 (ml)
Depth
11 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Jefferson County, 41 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3069 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 23 km (14 mi) from the epicentre. In Whitehall, 20 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.

Likely felt in: Whitehall 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 4.0 on 2016-09-03 — about 99 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 6.6 The 1925 Clarkston Valley, Montana Earthquake · 45 km NE of this epicentre
  2. 6.4 Clarkston Valley, Montana (Aftershock) · 45 km NE of this epicentre
  3. 5.5 Clarkston Valley, Montana (Aftershock) · 45 km NE of this epicentre
  4. 5.5 Clarkston Valley, Montana (Aftershock) · 45 km NE of this epicentre
  5. 5.5 Clarkston Valley, Montana (Aftershock) · 45 km NE 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 45.7713, -111.8864. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Jefferson County, MT 41 km (26 mi) NNW earthquakes near Jefferson County
Madison County, MT 50 km (31 mi) S earthquakes near Madison County
Silver Bow County, MT 62 km (38 mi) WNW earthquakes near Silver Bow County
Gallatin County, MT 63 km (39 mi) ESE earthquakes near Gallatin County
Broadwater County, MT 69 km (43 mi) NNE earthquakes near Broadwater County
Deer Lodge County, MT 104 km (64 mi) WNW earthquakes near Deer Lodge 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 1 km W of Manhattan, Montana
  2. 2.3 1 km WNW of Manhattan, Montana
  3. 1.6 1 km WNW of Manhattan, Montana
  4. 2.0 1 km W of Manhattan, Montana
  5. 2.2 2 km WNW of Manhattan, Montana
  6. 2.2 2 km W of Manhattan, Montana
  7. 1.8 1 km WNW of Manhattan, Montana
  8. 1.9 1 km W of Manhattan, Montana
  9. 1.8 1 km WNW of Manhattan, Montana
  10. 1.5 2 km SW of Manhattan, Montana
  11. 1.7 0 km W of Manhattan, Montana
  12. 1.8 2 km WNW of Manhattan, Montana
  13. 2.1 1 km W of Manhattan, Montana
  14. 2.0 2 km WNW of Manhattan, Montana
  15. 2.4 1 km WNW of Manhattan, 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.