M3.4 earthquake 203 km SSW of Nikolski, Alaska
A magnitude 3.4 earthquake struck 203 km SSW of Nikolski, Alaska on Fri, May 21, 2021, 1:20 AM HADT (10:20 UTC), 10 km (6 mi) below the surface.
A larger quake followed: M3.8 154 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
- 3.4 (mb), minor
- Local time
- UTC
- 2021-05-21 10:20:10 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 51.407° N, 170.479° 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.
- Location uncertainty
- About 8.4 km horizontally, 2.0 km in depth
- Magnitude uncertainty
- ±0.08
- Depth from
- Operator assigned
- Station coverage gap
- 220°, poorly surrounded by stations
- Stations used
- 57
Nearby
Within 100 km, magnitude 1.5 and up: 10 in the 60 days after this one and 1 in the 30 days before it.
After
- 3.8154 km SW of Nikolski, Alaska · 1949 days ago · 35 km deep · 64 km away
- 3.4258 km SSW of Nikolski, Alaska · 1946 days ago · 16 km deep · 58 km away
- 3.6115 km SW of Nikolski, Alaska · 1943 days ago · 22 km deep · 93 km away
- 3.3153 km SSW of Nikolski, Alaska · 1932 days ago · 10 km deep · 76 km away
- 3.8223 km SW of Nikolski, Alaska · 1925 days ago · 29 km deep · 46 km away
- 2.6217 km ESE of Atka, Alaska · 1923 days ago · 10 km deep · 72 km away
- 2.8240 km SSW of Nikolski, Alaska · 1901 days ago · 12 km deep · 58 km away
- 2.8112 km SSW of Nikolski, Alaska · 1898 days ago · 35 km deep · 91 km away
- 2.2178 km SW of Nikolski, Alaska · 1897 days ago · 24 km deep · 71 km away
- 2.8114 km SW of Nikolski, Alaska · 1897 days ago · 26 km deep · 92 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000ef31. Read Thu, Sep 24, 2026, 2:13 AM UTC.