QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mb

219 km SW of Yakutat, Alaska

· 10 km deep · released about 30 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 4.2 (mb)
Depth
10 km below the surface
Felt
no reports yet
Measured shaking
intensity I (ShakeMap)
Nearest mapped fault
Gulf of Alaska shear zone, 5 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1627 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 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 5,600× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 250× the energy of this one
  3. Magna, Utah 2020 M 5.7 180× the energy of this one
  4. This earthquake M 4.2 about 30 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 63× 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 58.2570, -142.6120. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 241 km SW of Yakutat, Alaska
  2. 2.8 210 km SW of Yakutat, Alaska
  3. 2.1 228 km SW of Yakutat, Alaska
  4. 2.0 227 km SW of Yakutat, Alaska
  5. 2.5 260 km SW of Yakutat, Alaska
  6. 2.2 214 km SW of Yakutat, Alaska
  7. 1.8 235 km SW of Yakutat, Alaska
  8. 3.0 202 km SW of Yakutat, Alaska
  9. 2.5 266 km SW of Yakutat, Alaska
  10. 1.9 198 km WSW of Yakutat, Alaska
  11. 2.6 239 km SW of Yakutat, Alaska
  12. 2.3 232 km SW of Yakutat, Alaska
  13. 2.1 261 km SW of Yakutat, Alaska
  14. 2.3 253 km SW of Yakutat, Alaska
  15. 2.0 194 km WSW of Yakutat, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.