QuakeIndex

Earthquake · reviewed by a seismologist

M 4.4mb

84 km SW of Unalaska, Alaska

Yes. A magnitude 4.4 earthquake was recorded 84 km SW of Unalaska, Alaska, at 3:15 am AKST on 1 February 2025 (12:15 UTC), 78 km deep. 1 person has reported feeling it to USGS.

· 78 km deep · released about 60 tons 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 4.4 (mb)
Depth
78 km below the surface
Felt
1 report · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 578 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 104 km (65 mi) from the epicentre. 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 60 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 2,800× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 130× the energy of this one
  3. Magna, Utah 2020 M 5.7 89× the energy of this one
  4. This earthquake M 4.4 about 60 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 130× 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 5.6 on 2025-01-26 — about 63 times the energy of this one.

Before 2016, the USGS record lists 29 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.8 81 km E of Nikolski, Alaska · 39 km SSW of this epicentre
  2. 6.9 80 km E of Nikolski, Alaska · 44 km SSW of this epicentre
  3. 6.9 67 km SW of Unalaska, Alaska · 18 km NNE of this epicentre
  4. 6.8 81 km ENE of Nikolski, Alaska · 28 km SW of this epicentre
  5. 6.8 68 km SSW of Unalaska, Alaska · 32 km E 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 53.3352, -167.4282. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.6 73 km WSW of Unalaska, Alaska
  2. 1.7 73 km WSW of Unalaska, Alaska
  3. 2.1 71 km WSW of Unalaska, Alaska
  4. 3.7 80 km SW of Unalaska, Alaska
  5. 2.1 100 km E of Nikolski, Alaska
  6. 1.9 49 km SW of Unalaska, Alaska
  7. 2.2 87 km SSW of Unalaska, Alaska
  8. 1.8 73 km SW of Unalaska, Alaska
  9. 2.1 87 km SSW of Unalaska, Alaska
  10. 3.9 82 km SSW of Unalaska, Alaska
  11. 3.4 88 km SSW of Unalaska, Alaska
  12. 2.6 89 km SSW of Unalaska, Alaska
  13. 1.7 103 km E of Nikolski, Alaska
  14. 1.7 86 km ENE of Nikolski, Alaska
  15. 1.5 93 km SSW 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.

On USGS

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