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Magnitude 2.9 - 14 miles SW of Atka
January 13, 2023 01:04:28 AKST (January 13, 2023 10:04:28 UTC)
52.1089°N 174.499°W Depth 128.7 miles (208 km)
- 20 miles (32 km) E of Mt. Sergief
- 28 miles (45 km) E of Koniuji Island
- 38 miles (61 km) E of Atka Pass
- 43 miles (69 km) E of Kasatochi Island
- 69 miles (111 km) E of Great Sitkin Island
- 87 miles (141 km) W of Seguam Island
- 89 miles (144 km) E of Mt. Adagdak
- 93 miles (150 km) E of Adak
- 96 miles (155 km) E of Mt. Moffett
- 107 miles (173 km) W of Amukta Pass
- 108 miles (175 km) W of Amukta Pass
- 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.