Weekly Seismicity Report For October 11, 2021 to October 17, 2021

During the week of October 11, 2021, the Alaska Earthquake Center reported 917 earthquakes within the state. The largest earthquake was magnitude 6.9 that occurred on October 11 at 01:10:25 AKST (October 11, 09:10:25 UTC), 55 miles SE of Yantarni Volcano.  This was an aftershock of the magnitude 8.2 event on July 29th.  Most events greater than magnitude 3.5 occured along the Aleutians except for a magnitude 4.7 near Homer and a 3.5 near the Cantwell Glacier.  Aftershocks continue in the Simineof and Chignik rupture zones as well as near Yakutat and Icy Bay.  Approximately 90 aftershocks occured after the 6.9 earthquake.  23 icequakes were recorded in Prince William Sound, Icy Bay, and Yakutat.  3 events were reported as felt.

Notable Events in Descending Order of Magnitude

Magnitude 6.9, 55 miles SE of Yantarni Volcano, October 11 00:10:25 AKST
Magnitude 4.7, 8 miles SW of Clam Gulch, October 16 08:47:23 AKST
Magnitude 4.5, 50 miles SE of Mt. Sergief, October 11 09:25:46 AKST
Magnitude 4.3, 85 miles SE of Perryville, October 17 10:27:12 AKST
Magnitude 4.2, 57 miles SE of Yantarni Volcano, October 11 00:15:44 AKST
Magnitude 4.1, 56 miles SE of Yantarni Volcano, October 11 10:40:25 AKST
Magnitude 4.0, 87 miles SE of Chignik, October 14 17:50:29 AKST
Magnitude 3.9, 125 miles SE of Chignik, October 13 02:34:21 AKST
Magnitude 3.8, 43 miles SW of Kiska Volcano, October 14 12:30:55 AKST
Magnitude 3.6, 56 miles SE of Yantarni Volcano, October 11 04:59:32 AKST

This report was compiled by K. Becker

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.