Report on Etorofu-Yakeyama [Grozny Group] (Japan - administered by Russia) — 29 August-4 September 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 August-4 September 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Etorofu-Yakeyama [Grozny Group] (Japan - administered by Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 29 August-4 September 2012. Smithsonian Institution and US Geological Survey.
Etorofu-Yakeyama [Grozny Group]
Japan - administered by Russia
45.012°N, 147.871°E; summit elev. 1158 m
All times are local (unless otherwise noted)
Based on visual observations and analyses of satellite imagery, SVERT reported that during 23 August-3 September fumarolic activity at Grozny Group increased. The Aviation Color Code remained at Yellow.
Geologic Background. The Etorofu-Yakeyama (Ivan Grozny) complex is located in the center of Iturup Island. It has a 3-3.5 km diameter caldera open to the south, where a large extrusive andesitic dome was emplaced. Several other lava domes of Holocene age were constructed to the NE; extrusion of these domes has constricted a former lake in the northern side of the caldera to an extremely sinuous shoreline. Historical eruptions, the first of which took place in 1968, have been from the central Yakeyama (Grozny) dome.