QuakeIndex

Earthquake · reviewed by a seismologist

M 4.1mwr

70 km S of Nanwalek, Alaska

· 45 km deep · released about 21 tons of TNT

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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 4.1 (mwr)
Depth
45 km below the surface
Felt
no reports yet
Measured shaking
intensity III (ShakeMap)
Nearest
Kodiak Island Borough, 158 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1541 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

How big was it?

This earthquake released about 21 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 7,900× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 350× the energy of this one
  3. Magna, Utah 2020 M 5.7 250× the energy of this one
  4. This earthquake M 4.1 about 21 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 45× 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 58.7264, -152.0551. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kodiak Island Borough, AK 158 km (98 mi) NE of here earthquakes near Kodiak Island Borough

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

Aftershocks so far

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

  1. 1.6 30 km SSW of Nanwalek, Alaska
  2. 1.8 50 km NNE of Ouzinkie, Alaska
  3. 1.7 72 km SSW of Nanwalek, Alaska
  4. 2.7 27 km S of Nanwalek, Alaska
  5. 2.5 64 km NE of Aleneva, Alaska
  6. 2.1 75 km NNE of Aleneva, Alaska
  7. 1.9 41 km SSW of Nanwalek, Alaska
  8. 1.9 45 km SSW of Nanwalek, Alaska
  9. 1.8 40 km SSW of Nanwalek, Alaska
  10. 1.6 52 km SSW of Nanwalek, Alaska
  11. 1.6 23 km S of Nanwalek, Alaska
  12. 1.9 57 km NNE of Aleneva, Alaska
  13. 2.6 62 km NNE of Aleneva, Alaska
  14. 3.1 73 km S of Port Graham, Alaska
  15. 1.9 69 km NE of Ouzinkie, 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 5.8 on 2019-05-27 — it released about 350 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.