Magnitude 2.1 - 27 miles E of Atka

May 22, 2023 17:45:59 AKDT (May 23, 2023 01:45:59 UTC)
52.1729°N 173.5645°W Depth 26.0 miles (42 km)

This event has been reviewed by a seismologist

48 miles (77 km) W of Seguam Island
59 miles (95 km) E of Mt. Sergief
66 miles (107 km) E of Koniuji Island
67 miles (108 km) W of Amukta Pass
68 miles (110 km) W of Amukta Pass
78 miles (126 km) E of Atka Pass
83 miles (134 km) E of Kasatochi Island
106 miles (171 km) W of Chagulak Island
109 miles (176 km) E of Great Sitkin Island
125 miles (202 km) W of Yunaska Island
129 miles (209 km) E of Mt. Adagdak

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.