QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mwr

16 km NNW of Stanley, Idaho

· 9.7 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 62 kmBoise County 69 kmValley County 73 kmCamas County 97 kmLemhi County 110 kmElmore County 113 kmGem County 115 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 3.9 (mwr)
Depth
9.7 km below the surface
Felt
8 reports · strongest reported intensity III
Measured shaking
intensity IV (ShakeMap)
Nearest
Custer County, 62 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 407 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 8 people have reported feeling it to USGS.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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 44.3551, -115.0195. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Custer County, ID 62 km (38 mi) W of here earthquakes near Custer County
Boise County, ID 69 km (43 mi) NE of here earthquakes near Boise County
Valley County, ID 73 km (45 mi) SE of here earthquakes near Valley County
Camas County, ID 97 km (60 mi) NNW of here earthquakes near Camas County
Lemhi County, ID 110 km (68 mi) SW of here earthquakes near Lemhi County
Elmore County, ID 113 km (70 mi) NNE of here earthquakes near Elmore 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. 2.0 15 km NNW of Stanley, Idaho
  2. 2.3 15 km NNW of Stanley, Idaho
  3. 2.6 17 km NNW of Stanley, Idaho
  4. 2.6 15 km NNW of Stanley, Idaho
  5. 2.6 16 km NNW of Stanley, Idaho
  6. 1.5 12 km NNW of Stanley, Idaho
  7. 3.0 20 km NW of Stanley, Idaho
  8. 3.2 14 km NNW of Stanley, Idaho
  9. 3.9 17 km NW of Stanley, Idaho
  10. 3.0 17 km NNW of Stanley, Idaho
  11. 2.3 17 km NNW of Stanley, Idaho
  12. 2.1 13 km NNW of Stanley, Idaho
  13. 3.0 16 km NNW of Stanley, Idaho
  14. 2.0 15 km NNW of Stanley, Idaho
  15. 2.6 14 km NNW 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 7,900 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.