Alaska earthquakes

M2.8 earthquake 135 km SW of Adak, Alaska

A magnitude 2.8 earthquake struck 135 km SW of Adak, Alaska on Mon, Apr 19, 2021, 7:42 PM HADT (04:42 UTC), 35 km (22 mi) below the surface.

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

Map

Where this earthquake was located, with the others nearby. Select one for its page.

Open the live map with earthquakes

The earthquake

Magnitude: 2.8 (ml), micro
Local time: Mon, Apr 19, 2021, 7:42 PM HADT
UTC: 2021-04-20 04:42:53 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.191° N, 178.246° 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 2.9 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.12
Depth from: Operator assigned
Station coverage gap: 265°, poorly surrounded by stations
Stations used: 30

Nearby

Within 100 km, magnitude 1.5 and up: 77 in the 60 days after this one and 59 in the 30 days before it.

After

The first 60 of 77.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000e399 (also filed as ak02151zr0z9). Read Sat, Sep 26, 2026, 1:28 AM UTC.