M5.5 earthquake 103 km SSW of Adak, Alaska
A magnitude 5.5 earthquake struck 103 km SSW of Adak, Alaska on Sat, Feb 6, 1971, 4:20 PM GMT-11 (03:20 UTC), 35 km (22 mi) below the surface.
A larger quake followed: M5.8 95 km SSW 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
- 1971-02-07 03:20:59 UTC
- Depth
- 35.0 km (21.7 mi), shallow
- Epicenter
- 50.990° N, 177.120° 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
- ±0.20
- Depth from
- From location
Nearby
Within 100 km, magnitude 2.5 and up: 2 in the 60 days after this one and 4 in the 30 days before it.
After
- 5.590 km SSW of Adak, Alaska · 20312 days ago · 35 km deep · 14 km away
- 5.895 km SSW of Adak, Alaska · 20265 days ago · 25 km deep · 26 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event iscgem786964. Read Tue, Sep 22, 2026, 9:32 AM UTC.