Magnitude 5.4 - 24 miles NE of Attu
October 26, 2019 12:28:48 AKDT (October 26, 2019 20:28:48 UTC)
53.2129°N 173.5918°E Depth 6.2 miles (10 km)
This event has been reviewed by a seismologist
- 41 miles (66 km) NW of Shemya Is
- 114 miles (184 km) NW of Buldir Is
- 114 miles (184 km) NW of Buldir Island
- 184 miles (298 km) NW of Kiska Volcano
- 208 miles (337 km) NW of Segula Peak
- 217 miles (351 km) NW of Davidof Island
- 219 miles (355 km) NW of Little Sitkin Pass
- 256 miles (415 km) NW of Amchitka
- 267 miles (432 km) W of Semisopochnoi Island
- 327 miles (530 km) E of Bering Is, Komandorsky
- 335 miles (543 km) W of Mt. Gareloi
- Magnitude type: Mb2
- 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.