M5.5 earthquake 131 km SW of Nikolski, Alaska
A magnitude 5.5 earthquake struck 131 km SW of Nikolski, Alaska on Fri, Apr 9, 1971, 1:36 PM GMT-11 (00:36 UTC), 30 km (19 mi) below the surface.
A larger quake followed: M5.5 179 km SW of Nikolski, 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
- 1971-04-10 00:36:43 UTC
- Depth
- 30.0 km (18.6 mi), shallow
- Epicenter
- 51.977° N, 169.980° 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: 1 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event iscgem785492. Read Tue, Sep 22, 2026, 10:50 AM UTC.