QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

34 km NNW of Challis, Idaho

· 8.4 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lemhi County 43 kmCuster County 59 kmValley County 97 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
8.4 km below the surface
Felt
no reports yet
Nearest
Lemhi County, 43 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 459 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× 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 44.7958, -114.3933. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lemhi County, ID 43 km (26 mi) WSW of here earthquakes near Lemhi County
Custer County, ID 59 km (37 mi) N of here earthquakes near Custer County
Valley County, ID 97 km (60 mi) E of here earthquakes near Valley County
Beaverhead County, MT 124 km (77 mi) WSW of here earthquakes near Beaverhead County
Boise County, ID 138 km (86 mi) NE of here earthquakes near Boise County
Idaho County, ID 144 km (90 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

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

  1. 2.0 8 km SSW of Challis, Idaho
  2. 1.6 52 km NNW of Challis, Idaho
  3. 2.3 7 km E of Challis, Idaho
  4. 2.6 4 km NW of Challis, Idaho
  5. 2.4 2 km NW of Challis, Idaho
  6. 1.7 14 km NNE of Challis, Idaho
  7. 2.3 19 km NNE of Challis, Idaho
  8. 2.3 33 km NNW of Challis, Idaho
  9. 1.7 32 km NNW of Challis, Idaho
  10. 1.6 32 km NNW of Challis, Idaho
  11. 2.0 33 km NNW of Challis, Idaho
  12. 2.0 33 km NNW of Challis, Idaho
  13. 1.6 32 km NNW of Challis, Idaho
  14. 2.3 32 km NNW of Challis, Idaho
  15. 1.7 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.2 on 2025-01-27 — it released about 3,700 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.