M4.7 earthquake 197 km W of Adak, Alaska
A magnitude 4.7 earthquake struck 197 km W of Adak, Alaska on Wed, Jul 20, 1977, 12:36 AM GMT-10 (10:36 UTC), 33 km (21 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.7 (mb), light
- Local time
- UTC
- 1977-07-20 10:36:05 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 51.594° N, 179.454° 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.
- Depth from
- OPERATOR_ASSIGNED
- Stations used
- 28
Nearby
Within 100 km, magnitude 1.7 and up: 0 in the 60 days after this one and 0 in the 30 days before it.
None recorded.
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0000pt7. Read Tue, Sep 22, 2026, 7:31 AM UTC.