M4.0 earthquake 220 km SSW of Nikolski, Alaska
A magnitude 4.0 earthquake struck 220 km SSW of Nikolski, Alaska on Tue, Feb 2, 2021, 12:16 AM HAST (10:16 UTC), 10 km (6 mi) below the surface.
A larger quake followed: M4.3 127 km SSW 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
- 4.0 (mb), light
- Local time
- UTC
- 2021-02-02 10:16:42 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 51.090° N, 170.012° 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 3.9 km horizontally, 1.9 km in depth
- Magnitude uncertainty
- ±0.13
- Depth from
- Operator assigned
- Station coverage gap
- 142°
- Stations used
- 41
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 2 in the 30 days before it.
After
- 3.5160 km SW of Nikolski, Alaska · 2049 days ago · 35 km deep · 89 km away
- 4.3127 km SSW of Nikolski, Alaska · 2043 days ago · 35 km deep · 100 km away
- 3.4219 km SSW of Nikolski, Alaska · 2009 days ago · 10 km deep · 15 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000dfzj (also filed as ak0211iqsbzq). Read Sun, Sep 27, 2026, 7:41 AM UTC.