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Magnitude 7.1 - 53 miles SW of Mt. Gareloi
December 19, 2007 00:30:26 AKST (December 19, 2007 09:30:26 UTC)
51.1375°N 179.4411°W Depth 12.8 miles (20 km)
This event has been reviewed by a seismologist
- 70 miles (113 km) SE of Semisopochnoi Island
- 73 miles (118 km) E of Amchitka
- 76 miles (123 km) SW of Tanaga Volcano
- 101 miles (163 km) SW of Bobrof Island
- 109 miles (176 km) SE of Little Sitkin Pass
- 111 miles (179 km) SE of Davidof Island
- 112 miles (181 km) SW of Kanaga Volcano
- 121 miles (196 km) SE of Segula Peak
- 128 miles (207 km) SW of Mt. Moffett
- 130 miles (210 km) W of Adak
- 136 miles (220 km) SW of Mt. Adagdak
- Magnitude type: Mw2
- Event type: N/A
To view any current tsunami advisories for this and other events please visit www.tsunami.gov
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.