QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

41 km NNE of Spencer, Idaho

· 10 km deep · released about 480 lb of TNT

10 km30 km60 km120 km N Clark County 55 kmFremont County 61 kmMadison County 72 kmBeaverhead County 92 kmMadison County 101 kmJefferson County 103 kmGallatin County 111 kmTeton County 116 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
Magnitude
M 2.8 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Clark County, 55 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2444 days ago

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

How big was it?

This earthquake released about 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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.

Where

Epicentre 44.6749, -111.9161. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Clark County, ID 55 km (34 mi) NE of here earthquakes near Clark County
Fremont County, ID 61 km (38 mi) NW of here earthquakes near Fremont County
Madison County, MT 72 km (45 mi) S of here earthquakes near Madison County
Beaverhead County, MT 92 km (57 mi) ESE of here earthquakes near Beaverhead County
Madison County, ID 101 km (63 mi) NNW of here earthquakes near Madison County
Jefferson County, ID 103 km (64 mi) NNE of here earthquakes near Jefferson 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. 2.6 16 km NE of Lima, Montana
  2. 1.8 46 km NNE of Spencer, Idaho
  3. 1.6 24 km SSW of Virginia City, Montana
  4. 1.5 29 km S of Ennis, Montana
  5. 1.9 22 km WNW of Hebgen Lake Estates, Montana
  6. 1.5 26 km W of Hebgen Lake Estates, Montana
  7. 1.6 26 km W of Hebgen Lake Estates, Montana
  8. 1.9 23 km WSW of Hebgen Lake Estates, Montana
  9. 1.8 43 km NE of Spencer, Idaho
  10. 1.8 33 km S of Ennis, Montana
  11. 1.6 36 km N of Spencer, Idaho
  12. 1.8 29 km SSE of Virginia City, Montana
  13. 2.3 31 km SSE of Virginia City, Montana
  14. 2.1 26 km S of Virginia City, Montana
  15. 2.2 42 km W of Hebgen Lake Estates, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.3 on 2016-06-13 — it released about 200 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.