"Chuginadak Island"

Multiple pieces of evidence led scientists to the conclusion that there might be a 12-mile-wide caldera — a large volcanic crater — or a number of calderas, hidden underwater beneath the group of islands.

For the past two summers, an interdisciplinary team has visited the Islands of the Four Mountains, in the central Aleutians, to study how resilient the earliest settlers had to be to live there thousands of years ago.