M3.9 earthquake 136 km NE of Atka, Alaska
A magnitude 3.9 earthquake struck 136 km NE of Atka, Alaska on Sun, Oct 18, 2020, 7:44 PM HADT (04:44 UTC), 215 km (133 mi) below the surface.
A larger quake followed: M5.5 123 km NNE of Atka, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 3.9 (mb), minor
- Local time
- UTC
- 2020-10-19 04:44:14 UTC
- Depth
- 214.8 km (133.4 mi), intermediate-depth
- Epicenter
- 52.976° N, 172.644° 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 10.7 km horizontally, 11.5 km in depth
- Magnitude uncertainty
- ±0.12
- Depth from
- From location
- Station coverage gap
- 136°
- Stations used
- 46
Nearby
Within 100 km, magnitude 1.5 and up: 6 in the 60 days after this one and 1 in the 30 days before it.
After
- 2.841 km ENE of Atka, Alaska · 2165 days ago · 166 km deep · 97 km away
- 5.5123 km NNE of Atka, Alaska · 2161 days ago · 240 km deep · 57 km away · tsunami flag
- 4.3130 km ENE of Atka, Alaska · 2148 days ago · 138 km deep · 41 km away
- 3.6138 km E of Atka, Alaska · 2125 days ago · 103 km deep · 71 km away
- 2.786 km E of Atka, Alaska · 2117 days ago · 112 km deep · 100 km away
- 2.6144 km NE of Atka, Alaska · 2114 days ago · 145 km deep · 12 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000cc1x (also filed as ak020dgn3vtb). Read Mon, Sep 28, 2026, 8:49 AM UTC.