He is considered the most active volcano in the eastern Aleutengraben. The surrounding caldera of 9.5 km in diameter and 600 m depth is one of the largest in the world. It was created as a result of a volcanic eruption of magnitude 6 on the Vulkanexplosivitätsindex about 1645 BC. This outbreak is timely for Minoan eruption of the Santorini volcano, Aegean island and plays in the scientific debate about the dating of a certain role. Here material traces in ice cores, which were first assigned to Santorini, now associated with the Aniakchak.
Datings based on the Tephrochronologie ( tephra and ash deposits ) show some more powerful eruptions of the volcano. To 5250 BC ± 1000 years, a similarly strong outbreak as about 1645 BC ( ejection of at least 10 cubic kilometers of tephra ) occurred. Further eruptions occurred around the year 200, 1220 ± 150, 1390, and around 1560 ± 50 In so far last secured explosive eruption from 1 May to mid- June 1931 about 0.4 ± 0.05 cubic kilometers of tephra were ejected.
Since 1978, the volcano and its surroundings are as Aniakchak National Monument and Preserve nature reserve. In 1967 the crater of the Aniakchak was designated as a National Natural Landmark. From the Surprise Lake, a lake in the caldera, springs from the Aniakchak River.
The Mount Aniakchak was repeatedly explored in the 1930s by expeditions under the leadership of the scientist and Jesuit priest Bernard Hubbard, who toured the area both before and shortly after a major outbreak in 1931. This created numerous film footage and photographs, with which Hubbard held for many years lecture tours and Aniakchak ( Alaska and total ) by brought to a wider audience closer.