Tomariyama [Golovnin] Volcano — Japan - administered by Russia

Tomariyama, also known as Golovnin, forms the southern end of Kunashir Island, across the Nemuro Strait from Hokkaido. Explosive activity has dominated in the formation of this andesitic-dacitic volcano; no lava flows are exposed. The gently sloping stratovolcano is truncated by a 4-5 km caldera that formed during a series of late-Pleistocene eruptions beginning about 43,000 years ago. Several lava domes were subsequently emplaced on the caldera floor. Topographic highs outside the caldera rim are lava domes extruded along a ring structure or an outer caldera. A 1 x 2.5 km caldera lake on the northern side of the inner caldera drains through a narrow breach in the western caldera wall. Solfataric activity occurs at the northern lake shore and at explosion craters (one of which contains a hot crater lake with reported temperatures from 36-100°C) that cut the caldera-floor lava domes. The only known recorded eruption was a minor explosion in 1848.