QuakeIndex

Earthquake · reviewed by a seismologist

M 4.7mb

137 km SE of Akutan, Alaska

· 22 km deep · released about 170 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 4.7 (mb)
Depth
22 km below the surface
Felt
no reports yet
Measured shaking
intensity I (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1288 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 170 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 1,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 45× the energy of this one
  3. Magna, Utah 2020 M 5.7 32× the energy of this one
  4. This earthquake M 4.7 about 170 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 350× 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 53.2111, -164.3873. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.5 138 km SE of Akutan, Alaska
  2. 1.8 95 km SE of Akutan, Alaska
  3. 2.6 97 km SE of Akutan, Alaska
  4. 2.9 91 km SE of Akutan, Alaska
  5. 2.7 139 km SE of Akutan, Alaska
  6. 2.1 121 km SE of Akutan, Alaska
  7. 3.2 111 km SE of Akutan, Alaska
  8. 1.7 Unimak Island region, Alaska
  9. 2.2 105 km SE of Akutan, Alaska
  10. 1.8 104 km SE of Akutan, Alaska
  11. 2.0 141 km SSE of Akutan, Alaska
  12. 2.7 132 km SE of Akutan, Alaska
  13. 2.1 112 km SSE of Akutan, Alaska
  14. 2.0 97 km SE of Akutan, Alaska
  15. 2.0 97 km SE of Akutan, 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 5.1 on 2017-05-24 — it released about 4 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.