QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Andreanof Islands, Aleutian Islands, Alaska

· 10 km deep · released about 1.3 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 3.3 (ml)
Depth
10 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1265 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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 50.3533, -173.5157. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 4.4 213 km SSE of Atka, Alaska
  2. 3.9 221 km SSE of Atka, Alaska
  3. 2.5 201 km SSE of Atka, Alaska
  4. 4.0 209 km SSE of Atka, Alaska
  5. 3.4 204 km SSE of Atka, Alaska
  6. 2.9 178 km S of Atka, Alaska
  7. 2.7 203 km SSE of Atka, Alaska
  8. 2.5 212 km S of Atka, Alaska
  9. 2.1 185 km SSE of Atka, Alaska
  10. 2.3 182 km SSE of Atka, Alaska
  11. 2.7 176 km SSE of Atka, Alaska
  12. 3.3 217 km SSE of Atka, Alaska
  13. 2.9 173 km S of Atka, Alaska
  14. 2.2 194 km SSE of Atka, Alaska
  15. 3.5 198 km SSE of Atka, 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 4.5 on 2017-01-10 — it released about 63 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.