MONTH SEISMICITY REPORT FOR JULY 2023
During the month of July 2023, the Alaska Earthquake Center reported 4257 earthquakes within the state with magnitude ranging between 0.3 and 7.2 and depths between 0 and 230 km. The largest earthquake was magnitude 7.2 that occurred on July 15 at 22:48:21 AKDT (July 16, 06:48:21 UTC), 69 miles S of Sand Point. The main shock was followed by more than 200 aftershocks in July and was felt widely throughout the Aleutian Islands, the Alaskan Peninsula, and Cook Inlet regions. You can read more about this earthquake here:
Another notable earthquake of M4.5 occurred on July 3d at 6:47 am AKDT 2 miles S of Eagle River. This event was reported as being widely felt in the Anchorage and Mat-Su valley communities. 2191 felt reports were submitted.
We also reported 38 suspected quarry blasts located in the vicinity of Fort Knox, Usibelly and Livengood mines in Interior Alaska, and 123 ice quakes, primarily located in the Prince William Sound, Icy Bay, Yakutat Bay, at mount Ogden Wright glacier and mount Spurr Pothole Glacier. We also characterized 232 quakes as seismic events associated with volcanic activity, primarily located at Katmai volcanic group.
There were 15 earthquakes reported as felt in July.
NOTABLE EVENTS IN DESCENDING ORDER OF MAGNITUDE
Magnitude 7.2, 69 miles S of Sand Point, July 15 22:48:22 AKDT
Magnitude 5.7, 51 miles S of Sand Point, July 15 22:51:19 AKDT
Magnitude 5.0, 5 miles N of Little Sitkin Pass, July 19 15:56:05 AKDT
Magnitude 5.0, 19 miles NW of Mt. Douglas, July 28 11:11:22 AKDT
Magnitude 4.9, 69 miles S of Isanotski Peaks, July 17 13:59:05 AKDT
Magnitude 4.8, 12 miles S of Herbert Island, July 1 05:41:30 AKDT
Magnitude 4.7, 55 miles S of Sand Point, July 16 03:22:56 AKDT
Magnitude 4.7, 53 miles SW of Sand Point, July 26 07:29:19 AKDT
Magnitude 4.6, 72 miles SW of Akhiok, July 28 03:32:26 AKDT
Magnitude 4.5, 2 miles S of Eagle River, July 3 06:47:30 AKDT
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.