WEEK SEISMICITY REPORT FOR JULY 28, 2025 TO AUGUST 3, 2025
During the week of July 28, 2025, the Alaska Earthquake Center reported 666 earthquakes within the state. The largest earthquake was magnitude 3.7 that occurred on July 27 at 17:09:55 AKDT (July 28, 01:09:55 UTC), 31 miles S of Yunaska Island.
Another magnitude 3.7 event occurred on August 1, 2025 15:24:48 AKDT (August 1, 2025 23:24:48 UTC), 28 miles S of Beaver. This event was reported as felt in Fairbanks. A magnitude 2.9 event occurred on August 3, 2025 00:49:41 AKDT (August 3, 2025 08:49:41 UTC), 19 miles SW of Anchorage, which was reported as felt in Anchorage and the Mat-Su Valley.
Regarding the magnitude 7.3 Sand Point earthquake on July 16, the number of aftershocks decreased to approximately 300 events during this week, ranging from 1.4 to 3.6 in magnitude. For more information on the mainshock event, please see the seismicity report for July 14 to July 20, or the significant events page here.
We also observed an increase in activity S of False Pass this week, with 14 events ranging in magnitude from 2.2 to 3.7.
Volcanic activity near Mt. Spurr has been gradually increasing this month, with 17 events detected this week ranging in magnitude from 1.6 to 2.3.
Additionally, one icequake was recorded SE of Juneau during this week.
NOTABLE EVENTS IN DESCENDING ORDER OF MAGNITUDE
Magnitude 3.7, 31 miles S of Yunaska Island, July 27 17:09:55 AKDT
Magnitude 3.7, 34 miles S of Bobrof Island, July 28 21:03:58 AKDT
Magnitude 3.7, 90 miles SE of Westdahl Peak, July 29 10:22:20 AKDT
Magnitude 3.7, 28 miles S of Beaver, August 1 15:24:48 AKDT
Magnitude 3.6, 57 miles S of Sand Point, July 29 21:34:12 AKDT
Magnitude 3.6, 54 miles SE of Unalaska, July 31 06:21:34 AKDT
Magnitude 3.6, 58 miles S of Sand Point, August 1 23:49:05 AKDT
Magnitude 3.6, 56 miles S of Sand Point, August 2 05:32:56 AKDT
Magnitude 3.6, 58 miles S of Sand Point, July 28 23:22:14 AKDT
Magnitude 3.6, 40 miles S of Amukta Pass, August 2 19:34:59 AKDT
This report was compiled by Ayumi Bakken
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.