"Rishiri is a highly dissected andesitic stratovolcano that forms a 20-km-wide island west of the northern tip of Hokkaido. Extensive erosion has produced an extremely rugged topography, with a dramatic sharp-topped, 1719-m-high summit flanked by steep-sided radial ridges. A stratovolcano and flank lava domes were constructed at Rishiri beginning less than 200,000 years ago. Eruptions at the stratovolcano ceased about 37,000 years ago, after which only flank vents were active. Late-stage eruptions took place from scoria cones and maars along a 15-km-long NW-SE trend that extends to the SE coast. Flank eruptions were dominantly basaltic, but also included andesitic and rhyolitic activity. Extensive late-stage lava flows during the late Pleistocene form much of the northern and western coasts and extend offshore. The latest eruptions at Rishiri took place a few thousand years ago."  -Smithsonian Volcano Archive
Back to Top