MONTH SEISMICITY REPORT FOR SEPTEMBER 2024

During the month of September 2024, the Alaska Earthquake Center reported 3154 earthquakes within the state with magnitudes ranging between 0.5 and 5.4 and depths between 0 and 260 km. The largest earthquake was magnitude 5.4 that occurred on September 21 at 09:21:17 AKST, 45 miles S of Mt. Gareloi, in Andreanof Islands. This event was reported as felt in Adak. There were sixteen other earthquakes of magnitude greater than 4.0. They all were located along the subduction zone.

Six earthquakes were reported as felt in September. The largest number of DYFI (Did You Feel It) responses, 271, came from the M4.5 earthquake that occurred September 1st, at 5:20 am AKDT 1 mile E of Homer. It was reported as felt in the Kenai Peninsula communities and as far as in Anchorage. 

We also reported seismic sources that were other than regional tectonic earthquakes. Of these, 25 were suspected quarry blasts (magnitudes M=0.5-1.5), 101 icequakes (magnitudes M=0.8-2.4), primarily located in the Prince William Sound, Icy Bay, Yakutat Bay, and Brady glacier areas. 22 recorded quakes were associated with volcanic activity (M=0.8-2.2), most of which were located at  Katmai volcanic group and Mt Spurr.  Also six landslide  were recorded  in the interior of Alaska.

NOTABLE EVENTS IN DESCENDING ORDER OF MAGNITUDE


Magnitude 5.4, 45 miles S of Mt. Gareloi, September 21 09:21:18 AKDT
Magnitude 5.0, 28 miles E of Semisopochnoi Island, September 15 04:41:04 AKDT
Magnitude 4.6, 31 miles N of Mt. Gareloi, September 16 10:13:02 AKDT
Magnitude 4.5, 1 miles E of Homer, September 1 05:20:21 AKDT
Magnitude 4.5, 125 miles SE of Perryville, September 14 06:33:42 AKDT
Magnitude 4.4, 23 miles NE of Healy, September 25 23:25:08 AKDT
Magnitude 4.3, 22 miles SE of Atka, September 16 08:01:20 AKDT
Magnitude 4.3, 45 miles SE of Atka, September 6 09:16:16 AKDT
Magnitude 4.3, 18 miles SW of Tatitlek, September 15 07:17:05 AKDT
Magnitude 4.2, 53 miles SW of Kiska Volcano, September 18 21:05:29 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.