QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

20 km WSW of Challis, Idaho

· 10 km deep · released about 1.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 27 kmLemhi County 71 kmValley County 100 kmCamas County 108 kmBoise County 111 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 3.3 (ml)
Depth
10 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Custer County, 27 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 890 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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 44.4506, -114.4831. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Custer County, ID 27 km (17 mi) NW of here earthquakes near Custer County
Lemhi County, ID 71 km (44 mi) SW of here earthquakes near Lemhi County
Valley County, ID 100 km (62 mi) ESE of here earthquakes near Valley County
Camas County, ID 108 km (67 mi) NNE of here earthquakes near Camas County
Boise County, ID 111 km (69 mi) ENE of here earthquakes near Boise County
Blaine County, ID 125 km (78 mi) NNW of here earthquakes near Blaine County

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

Aftershocks so far

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

  1. 1.9 4 km NW of Stanley, Idaho
  2. 1.9 44 km NNE of Stanley, Idaho
  3. 1.6 21 km WSW of Challis, Idaho
  4. 1.6 44 km NNE of Stanley, Idaho
  5. 2.1 20 km NNW of Challis, Idaho
  6. 2.5 16 km SSE of Stanley, Idaho
  7. 2.3 16 km NE of Stanley, Idaho
  8. 2.2 4 km NW of Stanley, Idaho
  9. 1.9 5 km WNW of Stanley, Idaho
  10. 1.9 16 km NE of Stanley, Idaho
  11. 1.8 16 km NNE of Stanley, Idaho
  12. 2.6 14 km NNE of Stanley, Idaho
  13. 1.9 4 km NW of Stanley, Idaho
  14. 2.6 4 km NW of Stanley, Idaho
  15. 2.4 16 km NE of Stanley, 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 2020-06-09 — it released about 22 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.