Sashiusudake [Baransky]

Geography & Climate

Sashiusudake [Baransky] is located in Japan - administered by Russia, within the Kuril Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 45.10° N, 148.01° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 1,107 meters above sea level, Sashiusudake [Baransky] is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Sashiusudake [Baransky] 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 Sashiusudake [Baransky], 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

Sashiusudake [Baransky] has 3 recorded eruptions in the geological database, spanning from 1460 CE to 1951 CE. The most powerful recorded event was a gentle, effusive event in 1951 CE, reaching VEI 1 on the Volcanic Explosivity Index. These eruptions span roughly 491 years of volcanic history. The most recent eruption in 1951 CE places this volcano within the modern era of volcanological observation.

GVP Reference Summary

The Sashiusudake (also known as Baransky) volcanic complex along the Pacific coast in the central part of Iturup Island consists of an eroded Pleistocene volcano that is capped by a Holocene stratovolcano. A young summit lava dome is cut by a NW-trending chain of small explosion craters. A group of flank cones farther to the NW with a similar NW-SE orientation is partially surrounded by lava flows from the central crater of the andesitic-dacitic volcano. Lava flows from descended 4-5 km SE to reach the Pacific Ocean along a broad front. The only observed eruption occurred in 1951, when local inhabitants reported weak explosive activity at the summit. Strong solfataric activity continues from the summit and several flank craters, and the SW flank geothermal field contains hot springs and geysers. A small hydrothermal explosion took place in 1992 at an exploratory well in the SW-flank geothermal field.

— Smithsonian Institution, Global Volcanism Program