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Magnitude 2.6 - 44 miles S of Mt. Gareloi
May 21, 2023 07:58:59 AKDT (May 21, 2023 15:58:59 UTC)
51.1693°N 178.5252°W Depth 15.1 miles (24 km)
This event has been reviewed by a seismologist
- 52 miles (84 km) S of Tanaga Volcano
- 69 miles (111 km) SW of Bobrof Island
- 78 miles (126 km) SW of Kanaga Volcano
- 93 miles (150 km) SW of Mt. Moffett
- 94 miles (152 km) SW of Adak
- 97 miles (157 km) SE of Semisopochnoi Island
- 101 miles (163 km) SW of Mt. Adagdak
- 110 miles (178 km) E of Amchitka
- 120 miles (194 km) SW of Great Sitkin Island
- 143 miles (231 km) E of Little Sitkin Pass
- 146 miles (236 km) E of Davidof 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.