During the week of December 13, 2021, the Alaska Earthquake Center reported 891 earthquakes within the state. The largest earthquake was magnitude 4.7 that occurred on December 18 at 13:04:50 AKST (December 18, 22:04:50 UTC), 12 miles NE of Pedro Bay. All events greater than magnitude 3.5 were located along the subduction zone. Another notable event was a magnitude 3.4 earthquake on the Seward Penninsula, which was part of a swarm of about 30 events. Other areas of increased seismicity were the Eastern and Western Brooks Range, and Purcell Mountain area. Aftershocks were ongoing in the Chugiak, Simeonof, and offshore Kodiak zones. Glacial icequakes continued in Prince William Sound, Icy Bay, and Yakuat Bay. 2 events were reported as felt this week.
Magnitude 4.7, 12 miles NE of Pedro Bay, December 18 13:04:50 AKST
Magnitude 4.3, 90 miles SE of Perryville, December 13 15:02:12 AKST
Magnitude 4.0, 92 miles SE of Perryville, December 13 16:22:46 AKST
Magnitude 3.9, 33 miles S of Bobrof Island, December 13 16:15:32 AKST
Magnitude 3.8, 102 miles SE of Chignik, December 19 14:18:06 AKST
Magnitude 3.8, 3 miles SE of Segula Peak, December 17 01:53:50 AKST
Magnitude 3.6, 99 miles SE of Chignik, December 13 04:49:49 AKST
Magnitude 3.6, 32 miles S of Old Harbor, December 16 09:57:55 AKST
Magnitude 3.5, 7 miles N of Hope, December 17 02:01:47 AKST
Magnitude 3.5, 3 miles S of Davidof Island, December 15 01:24:49 AKST
This report was compiled by S. Cotton.
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 damage resulting from its authorized or unauthorized use.
For more information on earthquakes and seismology, contact the AEC at (907)-474-7320.