QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

47 km WSW of Atka, Alaska

Yes. A magnitude 3.2 earthquake was recorded 47 km WSW of Atka, Alaska at 10:21 UTC on 2023-01-13, 101 km deep.

· 101 km deep · released about 1,900 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 3.2 (ml)
Depth
101 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1335 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× 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.

For this area

The largest earthquake within 50 km since 2016 was M 5.3 on 2020-10-01 — about 1,400 times the energy of this one.

Before 2016, the USGS record lists 54 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 57 km SSW of Atka, Alaska · 43 km SE of this epicentre
  2. 6.5 25 km NW of Atka, Alaska · 42 km NNE of this epicentre
  3. 6.4 37 km WNW of Atka, Alaska · 33 km NNE of this epicentre
  4. 6.1 43 km S of Atka, Alaska · 46 km ESE of this epicentre
  5. 6.1 77 km SSW of Atka, Alaska · 49 km S of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 52.0073, -174.8205. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.8 80 km WSW of Atka, Alaska
  2. 1.7 66 km SW of Atka, Alaska
  3. 2.6 31 km SSW of Atka, Alaska
  4. 2.6 49 km S of Atka, Alaska
  5. 1.9 84 km SW of Atka, Alaska
  6. 2.6 54 km SSW of Atka, Alaska
  7. 1.7 71 km WSW of Atka, Alaska
  8. 1.8 45 km W of Atka, Alaska
  9. 2.9 59 km SSW of Atka, Alaska
  10. 2.0 Andreanof Islands, Aleutian Islands, Alaska
  11. 2.0 53 km WSW of Atka, Alaska
  12. 2.1 91 km SW of Atka, Alaska
  13. 1.9 69 km WSW of Atka, Alaska
  14. 1.9 78 km SW of Atka, Alaska
  15. 2.0 Andreanof Islands, Aleutian Islands, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.