Tomariyama [Golovnin]

Geography & Climate

Tomariyama [Golovnin] is located in Japan - administered by Russia, within the Kuril Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 43.84° N, 145.50° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 535 meters above sea level, Tomariyama [Golovnin] is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a caldera, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Tomariyama [Golovnin] sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Japan - administered by Russia near Tomariyama [Golovnin], this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Tomariyama [Golovnin] has 3 recorded eruptions in the geological database, spanning from 4550 BCE to 1848 CE. The most powerful recorded event was a gentle, effusive event in 1848 CE, reaching VEI 1 on the Volcanic Explosivity Index. These eruptions span roughly 6,398 years of volcanic history.

GVP Reference Summary

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.

— Smithsonian Institution, Global Volcanism Program