Magnitude 2.6 - 58 miles SE of Yantarni Volcano
October 12, 2021 23:09:45 AKDT (October 13, 2021 07:09:45 UTC)
56.2565°N 156.514°W Depth 28.7 miles (46 km)
This event has not been reviewed by a seismologist
- 63 miles (102 km) S of Mt. Chiginagak
- 72 miles (116 km) E of Chignik
- 72 miles (116 km) S of Kialagvik Creek
- 77 miles (124 km) SE of Aniakchak Crater
- 77 miles (124 km) E of Chignik Lagoon
- 89 miles (144 km) E of Black Peak
- 94 miles (152 km) S of Mt. Ugashik
- 94 miles (152 km) SE of Port Heiden
- 98 miles (158 km) SE of Pilot Point
- 101 miles (163 km) SW of Akhiok
- 104 miles (168 km) E of Perryville
- 187 miles (303 km) SW of Kodiak
- Magnitude type: Ml2
- Event type: earthquake
Tectonic Setting of the Alaska Peninsula
Seismicity in the Alaska Peninsula region is produced by different tectonic features: (1) The Aleutian megathrust is the source of the strongest earthquakes in the region. The most recent examples include the 2020 M7.8 Simeonof Earthquake under the Shumagin Islands and the 2021 M8.2 Chignik Earthquake southwest of Kodiak Island. While these recent earthquakes did not produce damaging tsunamis, previous tsunamis were documented in historical records of Russian communities and in recently discovered paleo-tsunami deposits. (2) Intermediate depth seismicity (below 20 miles/32 km) occurs in the Wadati-Benioff Zone, where the subducting Pacific Plate descends towards the mantle beneath the North American Plate. This zone extends along the Aleutian Arc, Alaska Peninsula, and Cook Inlet. In the Alaska Peninsula region, the seismicity abates at approximately 150 miles (241 km) depth, reflecting the down-dip extension of the Pacific Plate. The Aleutian-Alaska Wadati-Benioff Zone produces thousands of earthquakes each year, most of which are too deep and too small to be felt. The most notable examples of such earthquakes are the 1999 M7.0 and the 2001 M6.9 Kodiak Island events. Both earthquakes caused damage and disruption to the City of Kodiak and other communities on the island. (3) Crustal seismicity in this region can be attributed to the Kodiak Shelf Fault Zone and to the volcanic arc. In 1912, a series of M7+ earthquakes was associated with the Novarupta eruption, which was the largest volcanic eruption of the 20th century worldwide.