QuakeIndex

Earthquake · automatic estimate, may change

M 3.1ml

160 km SSE of Akhiok, Alaska

· 3.6 km deep · released about 1,300 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 3.1 (ml)
Depth
3.6 km below the surface
Felt
1 report · strongest reported intensity II
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 1877 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 55.5939, -153.2490. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.5 130 km SSE of Akhiok, Alaska
  2. 3.5 192 km SSE of Akhiok, Alaska
  3. 3.4 136 km SSE of Akhiok, Alaska
  4. 3.3 122 km SSE of Akhiok, Alaska
  5. 3.7 124 km SSE of Akhiok, Alaska
  6. 2.8 113 km SSE of Akhiok, Alaska
  7. 3.4 121 km SSE of Akhiok, Alaska
  8. 3.9 120 km SSE of Akhiok, Alaska
  9. 3.9 122 km SSE of Akhiok, Alaska
  10. 3.8 120 km SSE of Akhiok, Alaska
  11. 3.2 123 km SSE of Akhiok, Alaska
  12. 2.5 192 km SSE of Akhiok, Alaska
  13. 2.5 128 km SSE of Akhiok, Alaska
  14. 3.3 124 km SSE of Akhiok, Alaska
  15. 2.4 205 km SSE of Akhiok, 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 5.2 on 2020-04-17 — it released about 1,400 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.