QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7ml

97 km SSE of Nikolai, Alaska

· 7.9 km deep · released about 5.4 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 3.7 (ml)
Depth
7.9 km below the surface
Felt
no reports yet
Measured shaking
intensity IV (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 530 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 5.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 32,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,000× the energy of this one
  4. This earthquake M 3.7 about 5.4 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 11× 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 62.1760, -153.8111. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.8 79 km NE of Lime Village, Alaska
  2. 2.0 103 km SSE of Nikolai, Alaska
  3. 1.9 92 km ENE of Lime Village, Alaska
  4. 1.8 98 km SSE of Nikolai, Alaska
  5. 1.7 98 km S of Nikolai, Alaska
  6. 1.7 98 km SE of Nikolai, Alaska
  7. 1.6 101 km W of Skwentna, Alaska
  8. 2.5 89 km SSE of Nikolai, Alaska
  9. 1.7 100 km W of Skwentna, Alaska
  10. 2.0 101 km SSE of Nikolai, Alaska
  11. 1.7 88 km ENE of Lime Village, Alaska
  12. 1.9 100 km SSE of Nikolai, Alaska
  13. 2.1 108 km ENE of Lime Village, Alaska
  14. 2.2 97 km S of Nikolai, Alaska
  15. 2.3 106 km W of Skwentna, 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.