M4.0 earthquake 65 km S of Adak, Alaska
A magnitude 4.0 earthquake struck 65 km S of Adak, Alaska on Mon, Dec 19, 1977, 5:08 PM GMT-11 (04:08 UTC), 56 km (35 mi) below the surface.
A larger quake followed: M4.1 66 km SSE of Adak, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.0 (mb), light
- Local time
- UTC
- 1977-12-20 04:08:58 UTC
- Depth
- 56.0 km (34.8 mi), shallow
- Epicenter
- 51.286° N, 176.538° 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
- 12
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 4 in the 30 days before it.
After
- 4.166 km SSE of Adak, Alaska · 17808 days ago · 53 km deep · 18 km away
- 5.344 km ESE of Adak, Alaska · 17791 days ago · 63 km deep · 66 km away
- 3.947 km SW of Adak, Alaska · 17788 days ago · 121 km deep · 57 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0000s5a. Read Tue, Sep 22, 2026, 10:29 AM UTC.