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Magnitude 2.2 - 101 miles S of Adak
May 22, 2023 03:02:49 AKDT (May 22, 2023 11:02:49 UTC)
50.4346°N 177.0246°W Depth 15.7 miles (25 km)
This event has been reviewed by a seismologist
- 103 miles (167 km) S of Bobrof Island
- 103 miles (167 km) S of Kanaga Volcano
- 104 miles (168 km) S of Mt. Moffett
- 109 miles (176 km) S of Mt. Adagdak
- 111 miles (179 km) SE of Tanaga Volcano
- 119 miles (192 km) S of Great Sitkin Island
- 121 miles (196 km) SE of Mt. Gareloi
- 130 miles (210 km) SW of Atka Pass
- 136 miles (220 km) SW of Kasatochi Island
- 143 miles (231 km) SW of Mt. Sergief
- 148 miles (239 km) SW of Koniuji Island
- Magnitude type: Ml2
- 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.