QuakeIndex

Earthquake · reviewed by a seismologist

M 5.0mb

124 km SSW of Adak, Alaska

· 10 km deep · released about 480 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 5.0 (mb)
Depth
10 km below the surface
Felt
no reports yet
Measured shaking
intensity IV (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 587 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

How big was it?

This earthquake released about 480 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16× the energy of this one
  3. Magna, Utah 2020 M 5.7 11× the energy of this one
  4. This earthquake M 5.0 about 480 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 1,000× 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 50.8157, -177.1953. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 90 km SSW of Adak, Alaska
  2. 2.9 113 km SSW of Adak, Alaska
  3. 2.3 114 km SSW of Adak, Alaska
  4. 2.8 118 km SSW of Adak, Alaska
  5. 2.1 110 km SW of Adak, Alaska
  6. 2.5 111 km SSW of Adak, Alaska
  7. 2.7 105 km SSW of Adak, Alaska
  8. 3.0 121 km SSW of Adak, Alaska
  9. 2.1 108 km SSW of Adak, Alaska
  10. 3.4 123 km SSW of Adak, Alaska
  11. 3.4 124 km SSW of Adak, Alaska
  12. 3.9 123 km SSW of Adak, Alaska
  13. 3.3 110 km SSW of Adak, Alaska
  14. 2.2 129 km SSW of Adak, Alaska
  15. 2.8 137 km SSW of Adak, 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 6.3 on 2024-12-09 — it released about 89 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.