WEEK SEISMICITY REPORT FOR AUGUST 25, 2025 TO AUGUST 31, 2025

During the week of August 25, 2025, the Alaska Earthquake Center reported 376 earthquakes within the state. The largest earthquake was magnitude 5.9 that occurred on August 28 at 03:07:47 AKST (August 28, 11:07:47 UTC), 19 miles NE of Semisopochnoi Island.

This week, a magnitude 1.7 earthquake occurred just 1 mile SE of Fort Wainwright. This event was reported as felt throughout the areas of Fairbanks and North Pole.

Aftershocks from the M7.3 earthquake outside Sand Point on July 16th continue this week, with 65 aftershocks ranging from 1.8 to 5.0 in magnitude. The M5.0 aftershock was felt in the areas of Sand Point and King's Cove.

Five landslides of interest were recorded this week. On the 28th and 30th, two landslides in the region of Harvard Glacier were recorded, with magnitudes of 1.4 and 1.6 respectively. Three landslides on the 27th, with a magnitude range of 1.6 to 1.9, occurred in the Tracy Arm region, near the South Sawyer Glacier. These landslides are linked with the M5.4 Tracy Arm landslide that occurred on the 10th of this month. For more information, please visit the significant events page.

NOTABLE EVENTS IN DESCENDING ORDER OF MAGNITUDE


Magnitude 5.9, 19 miles NE of Semisopochnoi Island, August 28 03:07:48 AKDT
Magnitude 5.1, 22 miles S of Semisopochnoi Island, August 29 01:14:25 AKDT
Magnitude 5.0, 58 miles S of Sand Point, August 26 00:03:47 AKDT
Magnitude 4.5, 51 miles S of Atka, August 31 13:19:45 AKDT
Magnitude 3.9, 20 miles SW of Seguam Island, August 28 09:59:59 AKDT
Magnitude 3.7, 65 miles S of Herbert Island, August 30 10:30:26 AKDT
Magnitude 3.6, 16 miles N of Koyuk, August 25 12:24:41 AKDT
Magnitude 3.5, 49 miles S of Atka, August 31 07:47:08 AKDT
Magnitude 3.5, 25 miles W of Amchitka, August 25 14:50:13 AKDT
Magnitude 3.4, 23 miles S of Semisopochnoi Island, August 29 14:12:17 AKDT

This report was compiled by Owen Simonds

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.