QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mwr

26 km NW of Stanley, Idaho

· 15 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Boise County 59 kmValley County 63 kmCuster County 76 kmGem County 102 kmCamas County 103 kmElmore County 111 kmAdams 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
15 km below the surface
Felt
28 reports · strongest reported intensity III
Measured shaking
intensity IV (ShakeMap)
Nearest
Boise County, 59 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2289 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 28 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 44.3724, -115.1973. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Boise County, ID 59 km (37 mi) NE of here earthquakes near Boise County
Valley County, ID 63 km (39 mi) SSE of here earthquakes near Valley County
Custer County, ID 76 km (47 mi) W of here earthquakes near Custer County
Gem County, ID 102 km (63 mi) ENE of here earthquakes near Gem County
Camas County, ID 103 km (64 mi) NNW of here earthquakes near Camas County
Elmore County, ID 111 km (69 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. 2.6 40 km NW of Stanley, Idaho
  2. 2.6 29 km NW of Stanley, Idaho
  3. 2.9 28 km NW of Stanley, Idaho
  4. 3.2 29 km NW of Stanley, Idaho
  5. 2.5 11 km NNW of Stanley, Idaho
  6. 3.0 26 km W of Stanley, Idaho
  7. 2.7 28 km NW of Stanley, Idaho
  8. 3.0 25 km NW of Stanley, Idaho
  9. 2.9 20 km NW of Stanley, Idaho
  10. 2.5 26 km NW of Stanley, Idaho
  11. 3.1 13 km WNW of Stanley, Idaho
  12. 2.5 21 km WNW of Stanley, Idaho
  13. 3.5 20 km WNW of Stanley, Idaho
  14. 2.5 29 km NW of Stanley, Idaho
  15. 2.8 15 km WNW 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.