Report on Sashiusudake [Baransky] (Japan - administered by Russia) — January 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 1 (January 1988)
Managing Editor: Lindsay McClelland.
Sashiusudake [Baransky] (Japan - administered by Russia) Crater lake level drops; flank fumarolic activity
Please cite this report as:
Global Volcanism Program, 1988. Report on Sashiusudake [Baransky] (Japan - administered by Russia) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 13:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198801-290080
Japan - administered by Russia
45.1°N, 148.019°E; summit elev. 1125 m
All times are local (unless otherwise noted)
During observations 4-7 October 1987, five fumaroles in an explosion crater on the SW flank were forcefully emitting vapor. Jets rose 3-5 m and had temperatures of 99-107°C. In the summit crater, a 40-m-diameter explosion crater in the lava dome contained a smaller lake than in the past. The lake was <0.2 m deep, the surface was only 10 x 15 m, and the water was cold. Weak vaporization was occurring at two points on the dome (vaporizing temperatures are 40-45°C). No fumaroles were observed but there were many areas of sulfur deposits.
Geological 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 historical 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.
Information Contacts: G. Steinberg, Yuzhno-Sakhalinsk.