QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

128 km S of Unalaska, Alaska

· 14 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
14 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1152 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

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 52.7249, -166.7268. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 132 km ESE of Nikolski, Alaska
  2. 2.0 126 km S of Unalaska, Alaska
  3. 3.2 Fox Islands, Aleutian Islands, Alaska
  4. 2.0 128 km S of Unalaska, Alaska
  5. 2.4 118 km SSW of Unalaska, Alaska
  6. 2.0 119 km S of Unalaska, Alaska
  7. 2.9 119 km S of Unalaska, Alaska
  8. 2.0 134 km S of Unalaska, Alaska
  9. 3.4 126 km S of Unalaska, Alaska
  10. 2.1 124 km S of Unalaska, Alaska
  11. 2.7 139 km S of Unalaska, Alaska
  12. 2.1 122 km S of Unalaska, Alaska
  13. 4.0 120 km S of Unalaska, Alaska
  14. 1.8 136 km S of Unalaska, Alaska
  15. 2.3 125 km S of Unalaska, 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 4.6 on 2016-07-10 — it released about 180 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.