QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

32 km S of Virginia City, Montana

Yes. A magnitude 2.2 earthquake was recorded 32 km S of Virginia City, Montana, at 2:16 am MST on 27 December 2023 (09:16 UTC), 9.5 km deep.

· 9.5 km deep · released about 69 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Madison County 36 kmBeaverhead County 80 kmGallatin County 81 kmClark County 87 kmFremont County 93 kmSilver Bow County 116 kmPark County 118 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
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 2.2 (ml)
Depth
9.5 km below the surface
Felt
no reports yet
Nearest
Madison County, 36 km N
Nearest mapped fault
Madison fault, 24 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1050 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 16 km (10 mi) from the epicentre. 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.

How big was it?

This earthquake released about 69 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 220,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 150,000× the energy of this one
  3. Around the size people start to feel M 3.0 14× the energy of this one
  4. This earthquake M 2.2 about 69 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 4.3 on 2016-06-13 — about 1,400 times the energy of this one.

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

  1. 6.1 30 km SSW of Big Sky, Montana · 27 km E of this epicentre
  2. 5.2 32 km WNW of Hebgen Lake Estates, Montana · 29 km ESE of this epicentre
  3. 5.2 26 km WNW of Hebgen Lake Estates, Montana · 35 km ESE of this epicentre
  4. 5.0 31 km W of Hebgen Lake Estates, Montana · 32 km SE of this epicentre
  5. 5.0 39 km W of Hebgen Lake Estates, Montana · 37 km SSE 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 44.9992, -111.8960. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Madison County, MT 36 km (23 mi) N earthquakes near Madison County
Beaverhead County, MT 80 km (50 mi) W earthquakes near Beaverhead County
Gallatin County, MT 81 km (51 mi) NE earthquakes near Gallatin County
Clark County, ID 87 km (54 mi) SSW earthquakes near Clark County
Fremont County, ID 93 km (58 mi) SSE earthquakes near Fremont County
Silver Bow County, MT 116 km (72 mi) NNW earthquakes near Silver Bow 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. 2.3 26 km W of Hebgen Lake Estates, Montana
  2. 3.1 27 km W of Hebgen Lake Estates, Montana
  3. 1.5 27 km W of Hebgen Lake Estates, Montana
  4. 2.0 27 km W of Hebgen Lake Estates, Montana
  5. 2.0 37 km W of Hebgen Lake Estates, Montana
  6. 1.9 21 km S of Ennis, Montana
  7. 1.6 28 km SE of Virginia City, Montana
  8. 2.3 47 km NW of Island Park, Idaho
  9. 1.6 31 km SSE of Virginia City, Montana
  10. 1.8 40 km NNE of Spencer, Idaho
  11. 2.0 11 km S of Ennis, Montana
  12. 1.9 26 km NNW of Hebgen Lake Estates, Montana
  13. 1.7 22 km WNW of Hebgen Lake Estates, Montana
  14. 1.6 43 km W of Hebgen Lake Estates, Montana
  15. 1.5 28 km S of Ennis, 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.