QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

21 km NNW of Challis, Idaho

· 17 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 44 kmLemhi County 49 kmValley County 100 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 2.9 (ml)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Custer County, 44 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1065 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 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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 44.6630, -114.3780. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Custer County, ID 44 km (28 mi) NNW of here earthquakes near Custer County
Lemhi County, ID 49 km (30 mi) SW of here earthquakes near Lemhi County
Valley County, ID 100 km (62 mi) ESE of here earthquakes near Valley County
Beaverhead County, MT 128 km (80 mi) WSW of here earthquakes near Beaverhead County
Boise County, ID 130 km (81 mi) NE of here earthquakes near Boise County
Butte County, ID 145 km (90 mi) NW of here earthquakes near Butte County

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

Aftershocks so far

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

  1. 2.0 43 km NNE of Stanley, Idaho
  2. 1.8 33 km NNW of Challis, Idaho
  3. 1.7 32 km NNW of Challis, Idaho
  4. 1.8 43 km NNE of Stanley, Idaho
  5. 2.0 44 km NNE of Stanley, Idaho
  6. 2.1 43 km NNE of Stanley, Idaho
  7. 2.7 32 km NNW of Challis, Idaho
  8. 1.6 20 km NNW of Challis, Idaho
  9. 1.8 20 km NW of Challis, Idaho
  10. 1.5 8 km ESE of Challis, Idaho
  11. 1.6 southern Idaho
  12. 1.8 43 km NNE of Stanley, Idaho
  13. 2.6 34 km NNW of Challis, Idaho
  14. 1.5 36 km W of Challis, Idaho
  15. 1.9 20 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.