QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

42 km W of Hebgen Lake Estates, Montana

Yes. A magnitude 1.8 earthquake was recorded 42 km W of Hebgen Lake Estates, Montana, at 5:05 am MST on 5 February 2022 (12:05 UTC), 9.4 km deep.

· 9.4 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fremont County 62 kmMadison County 66 kmClark County 71 kmGallatin County 96 kmBeaverhead County 101 kmMadison County 107 kmJefferson County 116 kmTeton 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
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
9.4 km below the surface
Felt
no reports yet
Nearest
Fremont County, 62 km SSE
Nearest mapped fault
Centennial fault, 15 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 1740 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 10 km (6 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 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

The largest earthquake within 50 km since 2016 was M 4.3 on 2016-06-13 — about 6,500 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1959 Hebgen Lake, Montana Earthquake · 42 km E of this epicentre
  2. 6.1 30 km SSW of Big Sky, Montana · 36 km NNE of this epicentre
  3. 5.2 32 km WNW of Hebgen Lake Estates, Montana · 19 km NE of this epicentre
  4. 5.2 26 km WNW of Hebgen Lake Estates, Montana · 21 km ENE of this epicentre
  5. 5.0 31 km W of Hebgen Lake Estates, Montana · 14 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 44.7485, -111.7283. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fremont County, ID 62 km (39 mi) SSE earthquakes near Fremont County
Madison County, MT 66 km (41 mi) NNW earthquakes near Madison County
Clark County, ID 71 km (44 mi) SW earthquakes near Clark County
Gallatin County, MT 96 km (60 mi) NNE earthquakes near Gallatin County
Beaverhead County, MT 101 km (63 mi) WNW earthquakes near Beaverhead County
Madison County, ID 107 km (66 mi) S earthquakes near Madison 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 28 km S of Ennis, Montana
  2. 1.6 34 km S of Virginia City, Montana
  3. 2.3 34 km S of Virginia City, Montana
  4. 1.5 28 km SE of Virginia City, Montana
  5. 2.4 27 km W of Hebgen Lake Estates, Montana
  6. 1.7 30 km NW of Hebgen Lake Estates, Montana
  7. 1.6 36 km NNE of Spencer, Idaho
  8. 2.0 38 km NNE of Spencer, Idaho
  9. 1.7 37 km SSE of Virginia City, Montana
  10. 1.9 29 km WNW of Hebgen Lake Estates, Montana
  11. 1.8 29 km NNE of Spencer, Idaho
  12. 1.5 29 km NNE of Spencer, Idaho
  13. 1.5 43 km NE of Spencer, Idaho
  14. 2.1 34 km S of Virginia City, Montana
  15. 1.5 35 km S of Virginia City, 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.