Alaska earthquakes

M4.5 earthquake 36 km W of Tyonek, Alaska

A magnitude 4.5 earthquake struck 36 km W of Tyonek, Alaska on Thu, Sep 21, 1978, 5:45 AM GMT-9 (14:45 UTC), 81 km (50 mi) below the surface.

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The earthquake

Magnitude
4.5 (mb), light
Local time
UTC
1978-09-21 14:45:19 UTC
Depth
81.0 km (50.3 mi), intermediate-depth
Epicenter
61.108° N, 151.808° 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.

Stations used
29

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 1 in the 60 days after this one and 0 in the 30 days before it.

After

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp0000wnm. Read Tue, Sep 22, 2026, 7:09 AM UTC.