QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

21 km NNW of Challis, Idaho

· 8.8 km deep · released about 37 lb of TNT

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10 km30 km60 km120 km N Custer County 45 kmLemhi County 48 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 2.1 (ml)
Depth
8.8 km below the surface
Felt
no reports yet
Nearest
Custer County, 45 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1074 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 37 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 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 44.6643, -114.3750. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Custer County, ID 45 km (28 mi) NNW of here earthquakes near Custer County
Lemhi County, ID 48 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 (79 mi) WSW of here earthquakes near Beaverhead County
Boise County, ID 131 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

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

  1. 2.1 21 km WSW of Challis, Idaho
  2. 1.9 20 km WSW of Challis, Idaho
  3. 1.8 21 km WSW of Challis, Idaho
  4. 2.2 21 km WSW of Challis, Idaho
  5. 2.2 20 km WSW of Challis, Idaho
  6. 2.8 20 km NNW of Clayton, Idaho
  7. 3.3 20 km WSW of Challis, Idaho
  8. 1.9 36 km W of Challis, Idaho
  9. 2.7 37 km W of Challis, Idaho
  10. 1.5 20 km NNW of Challis, Idaho
  11. 2.4 20 km NNW of Challis, Idaho
  12. 2.5 21 km NNW of Challis, Idaho
  13. 3.3 24 km NW of Challis, Idaho
  14. 1.6 34 km NW of Challis, Idaho
  15. 1.7 21 km NNW 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

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