Aleutian Islands, Alaska
51.885 N, 178.146 W
summit elevation 1806 m
Tanaga volcano is located in the central Aleutian Islands, Alaska. The volcano consists of four eruption centres - Sajaka, Two Tanaga cones, and Takawangha. Most recent activity has occurred at Tanaga cone.
Tanaga Edifice Collapse
The south side of Tanaga volcano contains a collapse scar, which was produced by a massive edifice failure of the volcano, 140,000 to 240,000 years ago.
Seismic activity increased at Tanaga volcano in October 2005. Earthquakes increased from a background level of one per day in the previous two years, to 15-68 per day during the week of 5-11 October 2005. The earthquake epicentres were located about 2 km NE of the volcano's summi,t at depths of 10-20 km below sea level. The largest earthquake was magnitude 1.7. Earthquakes decreased at the end of November 2005.
1914, 1829, 1791?, 1763-70