QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

31 km SW of Karluk, Alaska

· 20 km deep · released about 1,300 lb of TNT

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10 km30 km60 km120 km N Kodiak Island Borough 65 km
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
20 km below the surface
Felt
no reports yet
Nearest
Kodiak Island Borough, 65 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1226 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 57.3438, -154.7857. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kodiak Island Borough, AK 65 km (41 mi) SW of here earthquakes near Kodiak Island Borough
Lake and Peninsula Borough, AK 129 km (80 mi) SE of here earthquakes near Lake and Peninsula Borough

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 1.9 32 km WNW of Karluk, Alaska
  2. 3.7 31 km WNW of Karluk, Alaska
  3. 3.0 51 km W of Akhiok, Alaska
  4. 2.0 14 km NNE of Karluk, Alaska
  5. 1.5 28 km WSW of Karluk, Alaska
  6. 2.0 68 km SW of Karluk, Alaska
  7. 2.6 29 km WNW of Karluk, Alaska
  8. 1.9 51 km W of Karluk, Alaska
  9. 1.6 43 km SSW of Karluk, Alaska
  10. 3.1 34 km SW of Karluk, Alaska
  11. 2.3 58 km WSW of Karluk, Alaska
  12. 1.9 16 km SW of Karluk, Alaska
  13. 2.6 48 km SW of Karluk, Alaska
  14. 1.9 30 km W of Karluk, Alaska
  15. 1.7 58 km SW of Karluk, 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 5.3 on 2021-02-13 — it released about 2,000 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.