QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

121 km SSE of Ugashik, Alaska

· 5.1 km deep · released about 7.6 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 1.6 (ml)
Depth
5.1 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1251 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 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 56.5728, -156.3956. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 128 km SSE of Ugashik, Alaska
  2. 2.6 114 km E of Chignik, Alaska
  3. 3.6 107 km E of Chignik, Alaska
  4. 2.2 99 km E of Chignik, Alaska
  5. 2.7 122 km SE of Ugashik, Alaska
  6. 2.2 116 km E of Chignik, Alaska
  7. 2.0 115 km ENE of Chignik, Alaska
  8. 2.1 109 km W of Akhiok, Alaska
  9. 1.8 127 km E of Chignik, Alaska
  10. 2.2 107 km SSE of Ugashik, Alaska
  11. 2.4 114 km E of Chignik, Alaska
  12. 1.6 106 km W of Akhiok, Alaska
  13. 3.1 124 km E of Chignik, Alaska
  14. 2.4 123 km E of Chignik, Alaska
  15. 3.2 102 km ENE of Chignik, 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 6.9 on 2021-10-11 — it released about 89,000,000 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.