QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

161 km S of False Pass, Alaska

· 20 km deep · released about 43 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 2.1 (ml)
Depth
20 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 406 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 53.4056, -163.5629. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 123 km SSW of False Pass, Alaska
  2. 2.3 132 km S of False Pass, Alaska
  3. 2.5 155 km S of False Pass, Alaska
  4. 2.4 143 km S of False Pass, Alaska
  5. 2.3 124 km ESE of Akutan, Alaska
  6. 2.8 128 km ESE of Akutan, Alaska
  7. 3.8 146 km S of False Pass, Alaska
  8. 2.7 159 km ESE of Akutan, Alaska
  9. 2.9 148 km ESE of Akutan, Alaska
  10. 2.9 147 km S of False Pass, Alaska
  11. 2.4 122 km S of False Pass, Alaska
  12. 2.6 121 km S of False Pass, Alaska
  13. 2.9 128 km S of False Pass, Alaska
  14. 3.2 134 km S of False Pass, Alaska
  15. 2.6 112 km S of False Pass, 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 5.9 on 2016-10-27 — it released about 500,000 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.