QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Idaho-Montana border region

· 3.5 km deep · released about 44 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lemhi County 44 kmCuster County 88 kmValley County 98 kmRavalli County 116 kmBeaverhead County 120 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 2.1 (ml)
Depth
3.5 km below the surface
Felt
no reports yet
Nearest
Lemhi County, 44 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2688 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 44 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 45.0610, -114.4128. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lemhi County, ID 44 km (27 mi) WNW of here earthquakes near Lemhi County
Custer County, ID 88 km (55 mi) N of here earthquakes near Custer County
Valley County, ID 98 km (61 mi) ENE of here earthquakes near Valley County
Ravalli County, MT 116 km (72 mi) SSW of here earthquakes near Ravalli County
Beaverhead County, MT 120 km (74 mi) W of here earthquakes near Beaverhead County
Idaho County, ID 120 km (75 mi) SE of here earthquakes near Idaho County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 2.5 33 km NNW of Challis, Idaho
  2. 2.5 33 km NNW of Challis, Idaho
  3. 2.0 southern Idaho
  4. 1.8 32 km NNW of Challis, Idaho
  5. 2.0 34 km NNW of Challis, Idaho
  6. 1.6 18 km NW of Challis, Idaho
  7. 2.2 24 km NW of Challis, Idaho
  8. 1.6 33 km NNW of Challis, Idaho
  9. 2.3 21 km NNW of Challis, Idaho
  10. 1.7 21 km NNW of Challis, Idaho
  11. 2.1 southern Idaho
  12. 3.4 24 km NNW of Challis, Idaho
  13. 3.2 20 km NW of Challis, Idaho
  14. 1.5 21 km NNW of Challis, Idaho
  15. 2.6 18 km NW of Challis, Idaho

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.