QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

46 km NNE of Spencer, Idaho

· 4.5 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Clark County 60 kmMadison County 64 kmFremont County 71 kmBeaverhead County 84 kmGallatin County 106 kmJefferson County 110 kmMadison County 110 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 1.8 (ml)
Depth
4.5 km below the surface
Felt
no reports yet
Nearest
Clark County, 60 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2049 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 44.7533, -111.9730. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Clark County, ID 60 km (37 mi) NNE of here earthquakes near Clark County
Madison County, MT 64 km (40 mi) S of here earthquakes near Madison County
Fremont County, ID 71 km (44 mi) NNW of here earthquakes near Fremont County
Beaverhead County, MT 84 km (52 mi) ESE of here earthquakes near Beaverhead County
Gallatin County, MT 106 km (66 mi) SW of here earthquakes near Gallatin County
Jefferson County, ID 110 km (68 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

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

  1. 2.9 6 km ENE of Lima, Montana
  2. 1.5 9 km ENE of Lima, Montana
  3. 1.6 41 km S of Virginia City, Montana
  4. 1.6 Idaho-Montana border region
  5. 1.7 31 km N of Spencer, Idaho
  6. 1.6 20 km W of Hebgen Lake Estates, Montana
  7. 1.6 10 km ESE of Lima, Montana
  8. 2.1 25 km WNW of Hebgen Lake Estates, Montana
  9. 1.7 42 km NNE of Spencer, Idaho
  10. 1.9 32 km N of Spencer, Idaho
  11. 2.0 28 km N of Spencer, Idaho
  12. 1.6 8 km ENE of Lima, Montana
  13. 2.1 32 km S of Virginia City, Montana
  14. 1.9 30 km WNW of Hebgen Lake Estates, Montana
  15. 2.4 8 km SE of Lima, 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 4.6 on 2019-04-09 — it released about 17,000 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.