QuakeIndex

Earthquake · reviewed by a seismologist

M 5.1mb

132 km SW of Nikolski, Alaska

· 54 km deep · released about 670 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 5.1 (mb)
Depth
54 km below the surface
Felt
no reports yet
Measured shaking
intensity III (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1147 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

How big was it?

This earthquake released about 670 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11× the energy of this one
  3. Magna, Utah 2020 M 5.7 7.9× the energy of this one
  4. This earthquake M 5.1 about 670 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 1,400× 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 52.2843, -170.5004. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.0 138 km SW of Nikolski, Alaska
  2. 3.4 165 km WSW of Nikolski, Alaska
  3. 3.0 151 km SW of Nikolski, Alaska
  4. 2.5 121 km SW of Nikolski, Alaska
  5. 3.7 123 km SW of Nikolski, Alaska
  6. 4.4 137 km SW of Nikolski, Alaska
  7. 4.9 137 km SW of Nikolski, Alaska
  8. 4.4 123 km SW of Nikolski, Alaska
  9. 4.9 130 km SW of Nikolski, Alaska
  10. 2.7 136 km SW of Nikolski, Alaska
  11. 3.4 129 km SW of Nikolski, Alaska
  12. 3.6 131 km SW of Nikolski, Alaska
  13. 2.9 135 km WSW of Nikolski, Alaska
  14. 2.4 137 km SW of Nikolski, Alaska
  15. 3.3 133 km WSW of Nikolski, 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 4.5 on 2017-03-07.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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