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M5.5 Depth: 35.0 km

M5.5 Earthquake near Alaska (United States)

UTC time: 2025-09-21 09:30:30 UTC Local time: —

About this earthquake

On September 21, 2025 at 09:30 UTC, a magnitude M5.5 earthquake occurred near Alaska (United States). The hypocenter lay relatively close to the surface at around 35 km, increasing how strongly it was felt. Events of this size can cause damage near the epicenter.

The event was recorded by USGS. United States: 152 earthquakes were recorded in the past 24 hours, the strongest reaching M3.8.

Details

Magnitude
M5.5
Depth
35.0 km
UTC time
2025-09-21 09:30:30 UTC
Local time
—
Country
United States
City
Alaska
Source
usgs
Coordinates
51.35900, -178.13390
Temperature
7.8°C

Map

Depth profile

Depth profile Depth: 35 km (Shallow) Surface Shallow Intermediate Deep 0 km 70 km 300 km 700 km 35 km
Shallow
35 km
35 km — deeper than the regional average (15.9 km)
Regional average: 15.9 km
Why depth matters

Shallow quakes release energy near the surface — shaking is felt more strongly and damage potential is higher.

Depth classes per USGS

Volcanoes nearby

  • Takawangha
    Distance: 58 km ·Stratovolcano ·Elevation: 1'449 m ·Last eruption: 1550 ·United States
  • Tanaga
    Distance: 58 km ·Stratovolcano(es) ·Elevation: 1'806 m ·Last eruption: 1914 ·United States
  • Gareloi
    Distance: 66 km ·Stratovolcano ·Elevation: 1'573 m ·Last eruption: 1989 ·United States
  • Bobrof
    Distance: 78 km ·Stratovolcano ·Elevation: 738 m ·United States
  • Kanaga
    Distance: 92 km ·Stratovolcano ·Elevation: 1'307 m ·Last eruption: 2023 ·United States
  • Moffett
    Distance: 116 km ·Stratovolcano ·Elevation: 1'196 m ·Last eruption: -1600 ·United States

Subsequent earthquakes nearby

Events recorded after this earthquake within 150 km. They are not automatically classified as aftershocks.

First 6 hours1
First 24 hours1
First 72 hours1
Strongest subsequent eventM5.7
M5.72025-09-21 09:30:33 UTC12.7 kmAndreanof Islands, Aleutian Islands, United States [Sea: United States] M3.62025-09-24 21:21:20 UTC147.4 km89 km SSE of Adak, Alaska M3.42025-09-28 20:31:17 UTC95.9 km100 km S of Adak, Alaska M2.92025-10-04 18:45:13 UTC126.6 km244 km WSW of Adak, Alaska M4.02025-10-05 01:51:45 UTC94.9 km M4.32025-10-05 01:51:46 UTC97.3 km200 km W of Adak, Alaska M5.02025-10-11 13:51:15 UTC111.4 kmAndreanof Islands, Aleutian Islands M4.52025-10-11 13:51:18 UTC125.7 km M5.02025-10-20 18:45:26 UTC79.6 km M5.02025-10-20 18:45:29 UTC70.0 kmAndreanof Islands, Aleutian Islands

Historical context nearby

Comparison with recorded earthquakes before this event within 150 km.

Magnitude rank#7
Earlier events M≥456
Earlier events M≥523
Compared since2025-01-02

The QuakeMap24 comparison dataset begins on 2024-03-23. Earlier earthquakes may not be included.

Strongest earlier events

M6.22025-03-21 14:53:41 UTC145.4 km88 km SSE of Adak, Alaska M6.22025-03-21 14:53:43 UTC134.6 kmAndreanof Islands, Aleutian Islands M5.82025-08-28 11:07:47 UTC147.8 kmAlaska M5.62025-09-21 09:30:27 UTC22.4 km123 km SW of Adak, Alaska M5.62025-03-22 09:49:21 UTC142.3 km87 km SSE of Adak, Alaska

Historic earthquake map · United States

Open history map
Explore recent and long-term earthquake activity in this country. Use filters to narrow down by magnitude, depth, and date range.

Country statistics · United States

Country overview
View earthquake KPIs, strongest and latest events, and averages for this country.

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