羅臼岳

Rausudake is an andesitic-to-dacitic stratovolcano with summit lava domes on the Shiretoko Peninsula in NE Hokkaido. The 1660-m-high volcano is located along a ridge 5 km SW of Shiretoko-Iozan volcano, the NE-most Holocene volcano in Hokkaido. Young lava flows descend the NW flank and broad areas along the SE flank, and an older lava flow traveled about 9 km W, reaching the coast of the Sea of Okhotsk along a broad front. Eruptions produced pumiceous tephras with associated pyroclastic flows about 2200, 1400, and 800 years ago. Recent work has documented a pyroclastic-flow deposit that overlies the 1739 tephra from Tarumai volcano in SW Hokkaido. Stratigraphic relationships place this eruption, the most recent known from Rausudake, between about 1750 and 1850 CE.