During the month of December 2023, the Alaska Earthquake Center reported 3399 earthquakes within the state with magnitude ranging between 0.6 and 6.1, and depth between 0 and 250 km. The largest event was magnitude 6.1 that occurred on December 21 at 05:55:57 AKST (December 21, 14:55:57 UTC), 54 miles S of Atka Pass. About 50 aftershocks followed this event.  All earthquakes of magnitude 4.0 and greater occurred along the subduction zone, except the M 4.1 event,  45 miles S of Kaktovik.

We also reported seismic sources others than regional tectonic earthquakes. Of these, 37 were suspected quarry blasts (M0.9-1.8) located in the vicinity of either Fort Knox or Usibelli mines in interior Alaska, 51 ice quakes, primarily located in the Prince William Sound, Icy Bay, and Yakutat Bay areas, and 45 seismic events associated with volcanic activity (M0.9-3.2).  

Nine earthquakes were reported as being felt in December.


Magnitude 6.1, 54 miles S of Atka Pass, December 21 05:55:57 AKST
Magnitude 5.1, 42 miles SE of Kantishna, November 30 20:50:26 AKST
Magnitude 4.9, 54 miles S of Atka Pass, December 21 10:28:29 AKST
Magnitude 4.8, 71 miles S of Chagulak Island, December 4 01:19:03 AKST
Magnitude 4.7, 23 miles NW of Iliamna Volcano, December 16 10:24:40 AKST
Magnitude 4.7, 56 miles S of Tanaga Volcano, December 19 16:54:11 AKST
Magnitude 4.7, 88 miles SE of Westdahl Peak, December 25 08:32:35 AKST
Magnitude 4.6, 56 miles S of Atka Pass, December 21 08:03:44 AKST
Magnitude 4.5, 55 miles S of Tanaga Volcano, December 19 17:04:50 AKST
Magnitude 4.5, 58 miles SE of Akutan, December 26 21:16:42 AKST

This report was compiled by N.Kozyreva.

The data in this report are preliminary and subject to revision. The earthquake parameters have been determined by the AEC, with supplemental data provided by the USGS National Earthquake Information Center. The data are released on the condition that none of the cooperating agencies may be held liable for any damaged resulting from its authorized or unauthorized use.

For more information on earthquakes and seismology, contact the AEC at 907-474-7320.