M4.2 earthquake 229 km W of Adak, Alaska
A magnitude 4.2 earthquake struck 229 km W of Adak, Alaska on Mon, Dec 21, 1998, 12:04 AM HAST (10:04 UTC), 120 km (75 mi) below the surface.
A larger quake followed: M4.7 248 km W 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
- 4.2 (mb, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1998-12-21 10:04:14 UTC
- Depth
- 120.1 km (74.6 mi), intermediate-depth
- Epicenter
- 51.839° N, 179.970° 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
- FROM_LOCATION
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 3 in the 30 days before it.
After
- 3.6295 km W of Adak, Alaska · 10134 days ago · 33 km deep · 65 km away
- 3.6243 km W of Adak, Alaska · 10127 days ago · 88 km deep · 21 km away
- 4.7248 km W of Adak, Alaska · 10118 days ago · 170 km deep · 53 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0008zyt. Read Fri, Oct 2, 2026, 10:40 PM UTC.