Magnitude 3.5 - 112 miles S of Shemya Is
August 27, 2022 07:49:37 AKDT (August 27, 2022 15:49:37 UTC)
51.0909°N 174.0861°E Depth 12.9 miles (20 km)
This event has been reviewed by a seismologist
- 117 miles (189 km) SW of Buldir Is
- 118 miles (191 km) SW of Buldir Island
- 132 miles (214 km) S of Attu
- 166 miles (269 km) SW of Kiska Volcano
- 185 miles (299 km) W of Segula Peak
- 192 miles (311 km) W of Davidof Island
- 195 miles (316 km) W of Little Sitkin Pass
- 214 miles (346 km) W of Amchitka
- 244 miles (395 km) W of Semisopochnoi Island
- 310 miles (502 km) W of Mt. Gareloi
- 339 miles (549 km) W of Tanaga Volcano
- Magnitude type: Ml2
- Event type: earthquake
Tectonic Setting of the Aleutian Islands
The Aleutian Arc marks the region where the Pacific Plate subducts into the mantle beneath the North American Plate. It is a seismically active region, evidenced by the thousands of earthquakes occurring each year. Since 1900, this region has hosted several major megathrust earthquakes, including the 1957 M8.6 in the Andreanof Islands, the 1965 M8.7 in the Rat Islands, the 1986 M7.9 and the 1996 M7.9 in the Andreanof Islands, and the 2003 M7.8 in the Rat Islands. Together they have ruptured the entire length of the megathrust boundary in this region. Another notable source of seismicity in the arc is the zone 6-9 miles (10-15 km) wide of intermediate-depth earthquakes within the subducting Pacific Plate, known as the Wadati-Benioff Zone. The largest recorded intermediate-depth earthquake in this region was the 2014 M7.9 Little Sitkin event. A third source of seismicity in this region are shallow earthquakes associated with volcanic processes and crustal faults within the overriding North American Plate. They occur regularly and may produce vigorous aftershock or swarm-like sequences.