QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

4 km WNW of Challis, Idaho

· 6.8 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 27 kmLemhi County 55 kmValley County 112 kmCamas 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 1.8 (ml)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
Custer County, 27 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2694 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 16 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 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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 44.5197, -114.2810. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Custer County, ID 27 km (17 mi) N of here earthquakes near Custer County
Lemhi County, ID 55 km (34 mi) SW of here earthquakes near Lemhi County
Valley County, ID 112 km (70 mi) ESE of here earthquakes near Valley County
Camas County, ID 120 km (74 mi) NNE of here earthquakes near Camas County
Butte County, ID 128 km (80 mi) NW of here earthquakes near Butte County
Boise County, ID 129 km (80 mi) ENE of here earthquakes near Boise County

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

Aftershocks so far

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

  1. 2.1 13 km NW of Challis, Idaho
  2. 1.8 6 km NNW of Challis, Idaho
  3. 1.6 36 km SSW of Salmon, Idaho
  4. 1.7 southern Idaho
  5. 1.6 11 km SE of Challis, Idaho
  6. 2.1 14 km SE of Challis, Idaho
  7. 1.9 16 km SE of Challis, Idaho
  8. 2.4 17 km SSE of Clayton, Idaho
  9. 2.8 13 km SSE of Clayton, Idaho
  10. 1.6 7 km NW of Challis, Idaho
  11. 2.6 12 km SE of Challis, Idaho
  12. 2.1 10 km SE of Challis, Idaho
  13. 1.6 11 km WSW of Challis, Idaho
  14. 1.9 16 km NNE of Challis, Idaho
  15. 2.3 17 km NNE 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.