QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0mwr

19 km WSW of Salcha, Alaska

· 15 km deep · released about 15 tons of TNT

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10 km30 km60 km120 km N Fairbanks North Star Borough 43 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 4.0 (mwr)
Depth
15 km below the surface
Felt
277 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Fairbanks North Star Borough, 43 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1338 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 277 people have reported feeling it to USGS.

How big was it?

This earthquake released about 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 11,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
  3. Magna, Utah 2020 M 5.7 350× the energy of this one
  4. This earthquake M 4.0 about 15 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 32× 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 64.4814, -147.2927. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Fairbanks North Star Borough, AK 43 km (27 mi) WSW of here earthquakes near Fairbanks North Star Borough

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

Aftershocks so far

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

  1. 1.9 4 km SW of Salcha, Alaska
  2. 2.0 4 km SW of Salcha, Alaska
  3. 2.3 4 km WSW of Salcha, Alaska
  4. 2.3 4 km SW of Salcha, Alaska
  5. 3.7 5 km S of Salcha, Alaska
  6. 5.3 4 km SW of Salcha, Alaska
  7. 2.3 58 km SW of Salcha, Alaska
  8. 1.6 5 km SE of Farmers Loop, Alaska
  9. 1.5 2 km NNE of Badger, Alaska
  10. 1.7 19 km S of South Van Horn, Alaska
  11. 1.6 18 km S of South Van Horn, Alaska
  12. 2.0 8 km N of North Pole, Alaska
  13. 2.5 8 km NNE of Moose Creek, Alaska
  14. 1.5 Central Alaska
  15. 2.0 Central Alaska

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 4.8 on 2021-07-23 — it released about 16 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.