BackgroundThe very small, 1 x 1.5 km wide Koniuji Island, located between Atka and Kasatochi volcanoes, is the emergent top of a mostly submarine volcano. The summit of the mostly submerged volcano reaches only 273 m above sea level. The volcano, which lies about 20 km north of the western side of Atka Island, is deeply dissected, with a steep, arcuate cliff on the west. New argon-argon dating indicates that the island emerged above sea level aout 15,000 years ago, and that several lava flows and domes were erupted during the Holocene. The summit lava dome is younger than about 3000 years. Reports of historical eruptive activity may be erroneous and are considered to refer to eruptions of the relatively undissected Kasatochi volcano to the west.
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8