M4.6 earthquake 243 km WSW of Adak, Alaska
A magnitude 4.6 earthquake struck 243 km WSW of Adak, Alaska on Mon, Apr 11, 1977, 7:23 AM GMT-12 (19:23 UTC), 59 km (37 mi) below the surface.
A larger quake followed: M5.1 206 km W 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
- 4.6 (mb), light
- Local time
- UTC
- 1977-04-11 19:23:10 UTC
- Depth
- 59.0 km (36.7 mi), shallow
- Epicenter
- 51.106° N, 179.922° 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
- 20
Nearby
Within 100 km, magnitude 1.6 and up: 4 in the 60 days after this one and 1 in the 30 days before it.
After
- 5.1206 km W of Adak, Alaska · 18059 days ago · 46 km deep · 69 km away
- 4.4232 km WSW of Adak, Alaska · 18058 days ago · 64 km deep · 13 km away
- 4.7186 km WSW of Adak, Alaska · 18052 days ago · 33 km deep · 62 km away
- 4.5173 km W of Adak, Alaska · 18004 days ago · 56 km deep · 83 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0000nbv. Read Tue, Sep 22, 2026, 8:10 AM UTC.