M4.9 earthquake 139 km WSW of Adak, Alaska
A magnitude 4.9 earthquake struck 139 km WSW of Adak, Alaska on Tue, Dec 23, 1986, 10:48 PM HAST (08:48 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M6.2 194 km WSW 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
- 4.9 (mb), light
- Local time
- UTC
- 1986-12-24 08:48:40 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 51.488° N, 178.552° 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.
- Depth from
- OPERATOR_ASSIGNED
Nearby
Within 100 km, magnitude 1.9 and up: 6 in the 60 days after this one and 0 in the 30 days before it.
After
- 4.969 km SW of Adak, Alaska · 14513 days ago · 33 km deep · 88 km away
- 4.9146 km WSW of Adak, Alaska · 14506 days ago · 33 km deep · 13 km away
- 4.4219 km WSW of Adak, Alaska · 14503 days ago · 33 km deep · 82 km away
- 4.3Andreanof Islands, Aleutian Islands, Alaska · 14478 days ago · 102 km deep · 11 km away
- 6.2194 km WSW of Adak, Alaska · 14468 days ago · 33 km deep · 55 km away
- 5.4193 km WSW of Adak, Alaska · 14468 days ago · 33 km deep · 54 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp000313v. Read Tue, Sep 29, 2026, 2:56 AM UTC.