Strong M 6.0 earthquake near Andreanof Islands, Alaska

Earthquake registered as M 6.0 (USGS) occurred near Andreanof Islands, Alaska at 16:21 UTC on September 15, 2013. The epicenter was at the sea, located 83 km SSW of Atka, Aleutian Arc, Alaska at coordinates 51.540°N 174.794°W. The depth was at 22.8 km (14.2 miles). EMSC registered M 5.9 at a depth of 10 km.

This area is rattled with earthquake swarm since late August. Area south of Andreanof Islands sits on top of the subducted plate where the oceanic Pacific plate subducts the North American plate at a very high speed.

Intensity shake map (Credit: USGS)

The Aleutian arc extends approximately 3,000 km from the Gulf of Alaska in the east to the Kamchatka Peninsula in the west. It marks the region where the Pacific plate subducts into the mantle beneath the North America plate. This subduction is responsible for the generation of the Aleutian Islands and the deep offshore Aleutian Trench.

Here, motion is characterized by westward-increasing oblique convergence and Pacific plate subduction beneath thin oceanic lithosphere. Despite the obliquity of convergence, active volcanism and megathrust earthquakes are also present along this margin.

Recent earthquakes recorded by Alaska Earthquake Information Center. For updated map and list visit their website here.

Image credit: Alaska Earthquake Information Center

Seismotectonics of Aleutian Arc and vicinity (USGS)

Featured image credit: Leaflet — Tiles Courtesy of MapQuest — Portions Courtesy NASA/JPL-Caltech and U.S. Department of Agriculture, Farm Service Agency