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Magnitude 2.4 - 39 miles SW of Mt. Gareloi
May 21, 2023 19:59:00 AKDT (May 22, 2023 03:59:00 UTC)
51.3936°N 179.4297°W Depth 25.8 miles (41 km)
This event has been reviewed by a seismologist
- 57 miles (92 km) SE of Semisopochnoi Island
- 65 miles (105 km) SW of Tanaga Volcano
- 68 miles (110 km) E of Amchitka
- 92 miles (149 km) W of Bobrof Island
- 101 miles (163 km) E of Little Sitkin Pass
- 103 miles (167 km) E of Davidof Island
- 104 miles (168 km) W of Kanaga Volcano
- 113 miles (183 km) E of Segula Peak
- 121 miles (196 km) W of Mt. Moffett
- 124 miles (201 km) W of Adak
- 128 miles (207 km) W of Mt. Adagdak
- 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.