Snowy Mountain Volcano — United States

Snowy Mountain, located 15 km NE of Mount Katmai, is the SW-most of a chain of closely spaced volcanoes extending NE along the crest of the Alaska Range. More than 90% of the volcano is covered by glacial ice, which prompted the naming of the volcano by members of the 1917 Katmai Expedition. Two small andesitic-dacitic stratovolcanoes, SW Snowy and NE Snowy, originated about 200,000 years ago. Collapse of NE Snowy during the Holocene produced a large debris avalanche that traveled to the north and left a large breached crater inside which a blocky lava dome was constructed. Peat beneath an ash layer thought to be associated with the the lava dome was radiocarbon dated at about 250 +/- 70 years ago. No eruptive activity has been observed and documented. Wood and Kienle (1990) noted that an active fumarole field at the summit had melted holes through the ice, and there was a zone of shallow seismicity beneath that mountain that is probably due to the hydrothermal system.