QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

south of 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 1226 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 52.8266, -162.0921. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.9 204 km SSE of False Pass, Alaska
  2. 3.5 225 km SSE of False Pass, Alaska
  3. 3.2 227 km SSE of False Pass, Alaska
  4. 2.7 217 km SSE of False Pass, Alaska
  5. 3.1 236 km SSE of False Pass, Alaska
  6. 2.6 219 km S of King Cove, Alaska
  7. 2.8 232 km SSE of False Pass, Alaska
  8. 2.6 197 km SSE of False Pass, Alaska
  9. 2.8 212 km S of King Cove, Alaska
  10. 3.0 219 km SSE of King Cove, Alaska
  11. 4.2 225 km SSE of False Pass, Alaska
  12. 2.8 263 km SSE of False Pass, Alaska
  13. 2.0 215 km SSE of King Cove, Alaska
  14. 2.0 222 km S of King Cove, Alaska
  15. 3.2 211 km S of King Cove, 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 4.9 on 2020-11-04 — it released about 250 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.