- Earthquakes
- Tsunamis
- Seismic Network
- About Us
Magnitude 3.2 - 62 miles SE of Amchitka
May 18, 2023 09:02:11 AKDT (May 18, 2023 17:02:11 UTC)
51.0053°N 179.8309°W Depth 8.2 miles (13 km)
This event has been reviewed by a seismologist
- 70 miles (113 km) SW of Mt. Gareloi
- 70 miles (113 km) S of Semisopochnoi Island
- 95 miles (154 km) SW of Tanaga Volcano
- 101 miles (163 km) SE of Little Sitkin Pass
- 103 miles (167 km) SE of Davidof Island
- 112 miles (181 km) SE of Segula Peak
- 120 miles (194 km) SW of Bobrof Island
- 131 miles (212 km) SW of Kanaga Volcano
- 134 miles (217 km) SE of Kiska Volcano
- 148 miles (239 km) SW of Mt. Moffett
- 149 miles (241 km) SW of Adak
- 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.