M4.0 earthquake 259 km SSW of Adak, Alaska
A magnitude 4.0 earthquake struck 259 km SSW of Adak, Alaska on Wed, Jan 1, 2020, 12:28 AM HAST (10:28 UTC), 10 km (6 mi) below the surface.
A larger quake followed: M4.6 230 km SSW of Adak, 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, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2020-01-01 10:28:51 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 49.610° N, 177.534° W
- Region
- Alaska
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 4.0 | mb, body-wave | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.1 · 27 stations |
| 3.5 | ML, local (Richter) | Alaska Earthquake Center | Preliminary |
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 7.3 km horizontally, 2.0 km in depth
- Magnitude uncertainty
- ±0.10
- Depth from
- Operator assigned
- Station coverage gap
- 221°, poorly surrounded by stations
- Stations used
- 74
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 1 in the 30 days before it.
After
- 2.4242 km SSW of Adak, Alaska · 2466 days ago · 20 km deep · 67 km away
- 4.6230 km SSW of Adak, Alaska · 2439 days ago · 10 km deep · 46 km away
- 3.3168 km S of Adak, Alaska · 2413 days ago · 10 km deep · 96 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us70006t71 (also filed as ak0201tnsph). Read Sun, Oct 4, 2026, 12:24 PM UTC.