QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mwr

26 km NW of Clayton, Idaho

· 9.2 km deep · released about 30 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 36 kmLemhi County 85 kmValley County 90 kmBoise County 96 kmCamas County 101 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 4.2 (mwr)
Depth
9.2 km below the surface
Felt
328 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Custer County, 36 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 71 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 328 people have reported feeling it to USGS.

How big was it?

This earthquake released about 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 5,600× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 250× the energy of this one
  3. Magna, Utah 2020 M 5.7 180× the energy of this one
  4. This earthquake M 4.2 about 30 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 63× 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 44.4068, -114.6681. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Custer County, ID 36 km (23 mi) WNW of here earthquakes near Custer County
Lemhi County, ID 85 km (53 mi) SW of here earthquakes near Lemhi County
Valley County, ID 90 km (56 mi) ESE of here earthquakes near Valley County
Boise County, ID 96 km (59 mi) ENE of here earthquakes near Boise County
Camas County, ID 101 km (63 mi) N of here earthquakes near Camas County
Blaine County, ID 126 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

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

  1. 2.4 17 km NE of Stanley, Idaho
  2. 2.1 17 km NW of Stanley, Idaho
  3. 1.7 24 km NW of Stanley, Idaho
  4. 1.6 22 km NW of Stanley, Idaho
  5. 1.7 22 km NW of Stanley, Idaho
  6. 1.8 26 km NW of Clayton, Idaho
  7. 1.9 23 km NW of Stanley, Idaho
  8. 1.9 20 km WNW of Stanley, Idaho
  9. 1.8 16 km NE of Stanley, Idaho
  10. 1.6 16 km NE of Stanley, Idaho
  11. 1.9 21 km WNW of Stanley, Idaho
  12. 1.8 15 km NE of Stanley, Idaho
  13. 2.2 17 km NE of Stanley, Idaho
  14. 2.1 17 km NNE of Stanley, Idaho
  15. 2.3 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 6.5 on 2020-03-31 — it released about 2,800 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.