Magnitude 2.4 - 35 miles W of Mt. Gareloi

May 22, 2023 11:31:23 AKDT (May 22, 2023 19:31:23 UTC)
51.8681°N 179.594°W Depth 64.5 miles (104 km)

This event has been reviewed by a seismologist

35 miles (56 km) E of Semisopochnoi Island
62 miles (100 km) W of Tanaga Volcano
65 miles (105 km) E of Amchitka
86 miles (139 km) E of Little Sitkin Pass
89 miles (144 km) E of Davidof Island
92 miles (149 km) W of Bobrof Island
97 miles (157 km) E of Segula Peak
104 miles (168 km) W of Kanaga Volcano
121 miles (196 km) E of Kiska Volcano
122 miles (197 km) W of Mt. Moffett
125 miles (202 km) W of Adak

Magnitude type: M_l²
Event type: earthquake

Tectonic Setting of the Aleutian Islands

The world's largest earthquakes originate along convergent plate boundaries such as the Aleutian megathrust. Starting in 1938, a series of three great earthquakes ruptured the subduction zone along its entire length from the Alaska Peninsula to the western Aleutians with the exception of a small gap near the Shumagin Islands. The sequence began with a M8.2 earthquake southwest of Kodiak Island. A M8.6 in the Andreanof Islands followed in 1957, and the sequence concluded with the Rat Islands M8.7 in 1965. The Shumagin Gap still has not ruptured, but GPS observations suggest that little strain has built up in this region.

Another notable source of seismicity in the arc are the intermediate depth earthquakes within the subducting Pacific Plate, known as the Wadati-Benioff zone. The largest recorded earthquake of this kind was the 2014 M7.9 Little Sitkin event. Shallow earthquakes associated with volcano processes and crustal faults within the overriding North American plate occur regularly and may produce vigorous aftershock or swarm-like sequences.