Alaska earthquakes

M2.7 earthquake 178 km WSW of Adak, AK

A magnitude 2.7 earthquake struck 178 km WSW of Adak, AK on Sun, Apr 18, 2021, 9:33 PM HADT (06:33 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M4.2 122 km WSW of Adak, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 2.7 (ml), micro
Local time: Sun, Apr 18, 2021, 9:33 PM HADT
UTC: 2021-04-19 06:33:32 UTC
Depth: 33.0 km (20.5 mi), shallow
Epicenter: 51.095° N, 178.875° W
Region: Alaska
Tsunami flag: No
Status: Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 3.9 km horizontally, 10.0 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 296°, poorly surrounded by stations
Stations used: 18

Nearby

Within 100 km, magnitude 1.5 and up: 57 in the 60 days after this one and 35 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000e394 (also filed as ak02150dckmd). Read Sat, Sep 26, 2026, 2:27 AM UTC.