M5.5 earthquake 179 km SW of Nikolski, Alaska
A magnitude 5.5 earthquake struck 179 km SW of Nikolski, Alaska on Sun, May 9, 1971, 2:01 PM GMT-10 (00:01 UTC), 53 km (33 mi) below the surface.
A larger quake followed: M5.5 146 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, moment), moderate
- Magnitude from
- ISC-GEM global catalog
- Local time
- UTC
- 1971-05-10 00:01:18 UTC
- Depth
- 53.4 km (33.2 mi), shallow
- Epicenter
- 51.953° N, 170.945° 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: 3 in the 60 days after this one and 1 in the 30 days before it.
After
- 5.3223 km ESE of Atka, Alaska · 20209 days ago · 25 km deep · 67 km away
- 5.5146 km SW of Nikolski, Alaska · 20203 days ago · 25 km deep · 33 km away
- 5.4161 km SW of Nikolski, Alaska · 20186 days ago · 24 km deep · 36 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event iscgem784273. Read Sat, Oct 3, 2026, 1:57 AM UTC.