M5.5 earthquake 160 km WSW of Adak, Alaska
A magnitude 5.5 earthquake struck 160 km WSW of Adak, Alaska on Thu, May 11, 1939, 8:38 PM GMT-11 (07:38 UTC), 25 km (16 mi) below the surface.
A larger quake followed: M5.8 122 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
- 5.5 (mw), moderate
- Local time
- UTC
- 1939-05-12 07:38:00 UTC
- Depth
- 25.0 km (15.5 mi), shallow
- Epicenter
- 51.253° N, 178.730° 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
- ±0.25
- Depth from
- From location
Nearby
Within 100 km, magnitude 2.5 and up: 1 in the 60 days after this one and 1 in the 30 days before it.
After
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event iscgem901958. Read Sun, Sep 27, 2026, 11:45 AM UTC.