QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6ml

15 km NE of Challis, Idaho

· 7.3 km deep · released about 3.8 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lemhi County 39 kmCuster County 40 kmBeaverhead County 113 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 3.6 (ml)
Depth
7.3 km below the surface
Felt
9 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Nearest
Lemhi County, 39 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3795 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 9 people have reported feeling it to USGS.

How big was it?

This earthquake released about 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 45,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,400× the energy of this one
  4. This earthquake M 3.6 about 3.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 7.9× more

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 44.6168, -114.1212. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lemhi County, ID 39 km (24 mi) SSW of here earthquakes near Lemhi County
Custer County, ID 40 km (25 mi) NNE of here earthquakes near Custer County
Beaverhead County, MT 113 km (70 mi) WSW of here earthquakes near Beaverhead County
Valley County, ID 121 km (75 mi) ESE of here earthquakes near Valley County
Butte County, ID 128 km (80 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. 1.8 11 km SE of Challis, Idaho
  2. 1.8 8 km NNW of Challis, Idaho
  3. 1.6 22 km WNW of Challis, Idaho
  4. 1.5 9 km NW of Challis, Idaho
  5. 1.6 35 km ESE of Clayton, Idaho
  6. 1.7 34 km WNW of Challis, Idaho
  7. 2.2 1 km ENE of Challis, Idaho
  8. 1.6 8 km NNW of Challis, Idaho
  9. 1.7 2 km NW of Challis, Idaho
  10. 1.8 14 km NE of Challis, Idaho
  11. 1.9 16 km SSE of Challis, Idaho
  12. 1.7 29 km ESE of Clayton, Idaho
  13. 1.9 12 km SE of Challis, Idaho
  14. 1.7 17 km SE of Challis, Idaho
  15. 1.7 19 km NNW of Clayton, 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.