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. Etorofu-Yakeyama (Ivan Grozny), is located in the center of Iturup Island. It has a 3-3.5 km diameter caldera that is open to the south, where the 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 restricted to Etorofu-Yakeyama.