Alamagan, seen here from the W with two peaks on either side of a roughly 350-m-deep summit crater, is the emergent summit of a large submarine volcano. The exposed cone is largely Holocene in age and the SW flank contains a 1 x 1.6 km graben. Pyroclastic flow deposits have been dated at about 1,000 years old.

Photo by Norm Banks, 1981 (U.S. Geological Survey).

This image is made available as a Public Domain Work, but proper attribution is appreciated.

Keywords: island volcano | cone

Alamagan