QuakeIndex

Earthquake · reviewed by a seismologist

M 5.3mww

Earthquake near Dutch Harbor, AK

No earthquake was likely felt in Dutch Harbor in the 24 hours to 4:29 pm AKST (01:29 UTC). The last one was M 4.4, 117 km (73 mi) ESE, at 3:00 pm AKST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Dutch Harbor

This page: a magnitude 5.3 earthquake was recorded 23 km (15 mi) north of Dutch Harbor, AK, at 2:47 pm AKDT on 27 July 2025 (22:47 UTC), 83 km deep. 30 people have reported feeling it to USGS.

USGS: 23 km N of Dutch Harbor, Alaska

2:47 pm AKDT, Jul 27, 2025 · · 83 km deep · released about 1.3 kilotons 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
2:47 pm AKDT on 27 July 2025 ()
Where
23 km (15 mi) north of Dutch Harbor, AK · earthquakes near Dutch Harbor
Magnitude
M 5.3 (mww)
Depth
83 km below the surface
Felt
30 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 109 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

At this magnitude and depth, people at rest would likely notice it out to about 217 km (135 mi) from the epicentre. In Dutch Harbor, 23 km away, the estimate is intensity III (weak). 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.

Likely felt in: Unalaska 25 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5.6× the energy of this one
  3. Magna, Utah 2020 M 5.7 4× the energy of this one
  4. This earthquake M 5.3 about 1.3 kilotons of TNT
  5. Around the size people start to feel M 3.0 this one released 2,800× 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 (31 mi) since our catalogue begins in 2016. The previous largest was M 4.6 on 2018-11-15.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 27 km WNW of Dutch Harbor, Alaska · 24 km WSW of this epicentre
  2. 5.9 13 km NE of Dutch Harbor, Alaska · 20 km SE of this epicentre
  3. 5.4 26 km WSW of Dutch Harbor, Alaska · 37 km SW of this epicentre
  4. 5.3 22 km ENE of Dutch Harbor, Alaska · 27 km ESE of this epicentre
  5. 5.2 48 km WNW of Dutch Harbor, Alaska · 45 km WSW 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 54.0969, -166.6020. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.0 25 km ESE of Unalaska, Alaska
  2. 2.0 27 km W of Dutch Harbor, Alaska
  3. 2.3 6 km W of Dutch Harbor, Alaska
  4. 1.6 23 km ENE of Unalaska, Alaska
  5. 2.1 23 km SSE of Unalaska, Alaska
  6. 1.7 18 km SE of Unalaska, Alaska
  7. 1.9 4 km N of Dutch Harbor, Alaska
  8. 2.6 14 km ENE of Unalaska, Alaska
  9. 2.2 23 km S of Unalaska, Alaska
  10. 2.1 5 km W of Dutch Harbor, Alaska
  11. 1.8 6 km N of Dutch Harbor, Alaska
  12. 2.9 24 km SE of Unalaska, Alaska
  13. 2.1 12 km SSW of Unalaska, Alaska
  14. 2.1 6 km W of Dutch Harbor, Alaska
  15. 2.2 6 km WSW of Dutch 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.