QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

151 km WSW of Nikolski, Alaska

· 5.0 km deep · released about 85 lb 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 2.3 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1118 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 85 lb of TNT

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 52.6341, -171.0475. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 5.0 129 km WSW of Nikolski, Alaska
  2. 3.6 136 km WSW of Nikolski, Alaska
  3. 2.3 169 km WSW of Nikolski, Alaska
  4. 3.6 176 km WSW of Nikolski, Alaska
  5. 2.9 127 km W of Nikolski, Alaska
  6. 2.3 162 km W of Nikolski, Alaska
  7. 3.2 148 km WSW of Nikolski, Alaska
  8. 2.9 158 km WSW of Nikolski, Alaska
  9. 2.4 136 km W of Nikolski, Alaska
  10. 2.4 145 km WSW of Nikolski, Alaska
  11. 2.7 129 km W of Nikolski, Alaska
  12. 3.8 164 km WSW of Nikolski, Alaska
  13. 3.1 153 km WSW of Nikolski, Alaska
  14. 4.1 155 km WSW of Nikolski, Alaska
  15. 5.0 159 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 4.9 on 2021-05-04 — it released about 7,900 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.