QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

162 km WSW of Adak, Alaska

· 41 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
41 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 381 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 51.3160, -178.8037. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.9 170 km W of Adak, Alaska
  2. 1.5 124 km WSW of Adak, Alaska
  3. 2.1 147 km WSW of Adak, Alaska
  4. 1.9 149 km WSW of Adak, Alaska
  5. 1.6 181 km W of Adak, Alaska
  6. 1.6 134 km WSW of Adak, Alaska
  7. 1.7 135 km WSW of Adak, Alaska
  8. 2.6 162 km WSW of Adak, Alaska
  9. 1.7 159 km WSW of Adak, Alaska
  10. 2.0 207 km WSW of Adak, Alaska
  11. 2.5 174 km WSW of Adak, Alaska
  12. 1.8 193 km WSW of Adak, Alaska
  13. 1.7 194 km WSW of Adak, Alaska
  14. 1.8 147 km WSW of Adak, Alaska
  15. 2.1 167 km W 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 6.2 on 2017-05-08 — it released about 22,000 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.