Segula Volcano

Segula Volcano is a remote stratovolcano on Segula Island in Alaska’s Aleutian chain, built from an underwater platform shared with nearby volcanoes. Andesitic lava and pyroclastic material accumulated from eruptions beneath the sea until the island rose above water from depths of about 350 feet, and repeated eruptions then formed its steep, layered cone. Its structure includes overlapping lava flows, fragmental deposits, a fissure, and a small summit caldera, while the island’s rugged north coast and shallow reef hinder access. Although no historical eruptions are recorded and it is generally considered inactive, lightly eroded deposits and a submarine feature indicate activity may have continued within the last few hundred years.