M6.6 earthquake 276 km WSW of Adak, Alaska
A magnitude 6.6 earthquake struck 276 km WSW of Adak, Alaska on Thu, Mar 28, 1940, 12:31 AM GMT+12 (12:31 UTC), 50 km (31 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.6 (mw), strong
- Local time
- UTC
- 1940-03-27 12:31:25 UTC
- Depth
- 50.0 km (31.1 mi), shallow
- Epicenter
- 51.426° N, 179.431° E
- 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.
- Magnitude uncertainty
- ±0.22
- Depth from
- From location
Nearby
Within 100 km, magnitude 2.5 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 iscgem901254. Read Tue, Sep 22, 2026, 4:35 AM UTC.