QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2ml

8 km NNE of Old Harbor, Alaska

Yes. A magnitude 4.2 earthquake was recorded 8 km NNE of Old Harbor, Alaska, at 11:12 pm AKDT on 22 April 2026 (07:12 UTC), 39 km deep. 38 people have reported feeling it to USGS.

· 39 km deep · released about 30 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kodiak Island Borough 62 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 4.2 (ml)
Depth
39 km below the surface
Felt
38 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Kodiak Island Borough, 62 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 125 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 105 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 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 5,600× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 250× the energy of this one
  3. Magna, Utah 2020 M 5.7 180× the energy of this one
  4. This earthquake M 4.2 about 30 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 63× 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

Tied for the largest within 50 km (31 mi) since 2016, with M 4.2 on 2024-12-12.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 19 km SW of Old Harbor, Alaska · 27 km SW of this epicentre
  2. 6.0 15 km S of Larsen Bay, Alaska · 48 km WNW of this epicentre
  3. 5.9 25 km E of Old Harbor, Alaska · 26 km ESE of this epicentre
  4. 5.7 24 km S of Larsen Bay, Alaska · 44 km W of this epicentre
  5. 5.4 36 km SSW of Chiniak, Alaska · 49 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 57.2750, -153.2600. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kodiak Island Borough, AK 62 km (38 mi) NW earthquakes near Kodiak Island Borough

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

Aftershocks so far

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

  1. 2.0 17 km ESE of Larsen Bay, Alaska
  2. 2.2 31 km SSE of Old Harbor, Alaska
  3. 2.0 22 km WSW of Old Harbor, Alaska
  4. 1.6 22 km ENE of Larsen Bay, Alaska
  5. 2.4 25 km S of Womens Bay, Alaska
  6. 1.9 30 km SSE of Old Harbor, Alaska
  7. 1.8 23 km WNW of Old Harbor, Alaska
  8. 1.5 23 km NNW of Old Harbor, Alaska
  9. 3.2 24 km ENE of Akhiok, Alaska
  10. 2.1 34 km ENE of Larsen Bay, Alaska
  11. 2.1 37 km SW of Port Lions, Alaska
  12. 1.7 30 km N of Old Harbor, Alaska
  13. 2.4 35 km ESE of Old Harbor, Alaska
  14. 1.9 26 km SW of Old Harbor, Alaska
  15. 2.0 29 km WNW of Old Harbor, 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.