요테이산

Yoteizan is a symmetrical andesitic-to-dacitic stratovolcano NW of Toya caldera. Its summit is truncated by a 700-m-wide crater that is cut on its NW rim by overlapping smaller craters. Deep radial gullies cut the flanks. The latest eruption from the main edifice took place about 5,000-6,000 years ago. Hangetsu-ko (Half Moon Lake), a tuff cone on the lower NW flank, was estimated from stratigraphic evidence to have erupted about 3,000 years ago.