M5.9 earthquake 109 km WNW of Adak, Alaska
A magnitude 5.9 earthquake struck 109 km WNW of Adak, Alaska on Sun, Aug 4, 1940, 9:19 PM GMT-11 (08:19 UTC), 15 km (9 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.9 (mw), moderate
- Local time
- UTC
- 1940-08-05 08:19:48 UTC
- Depth
- 15.0 km (9.3 mi), shallow
- Epicenter
- 52.281° N, 178.090° 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.
- Magnitude uncertainty
- ±0.33
- 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 iscgem901522. Read Tue, Sep 22, 2026, 7:22 AM UTC.