Report on Etorofu-Yakeyama [Grozny Group] (Japan - administered by Russia) — 3 April-9 April 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 3 April-9 April 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Etorofu-Yakeyama [Grozny Group] (Japan - administered by Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 3 April-9 April 2013. 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)
SVERT reported that on 3 April at 0755 ash from Grozny Group fell in Kurilsk (23 km N) and Kitovy, producing deposits 2-3 mm thick. Cloud cover prevented observations of the volcano. The next day satellite images showed an ash plume that rose 3 km (10,000 ft) a.s.l. and drifted W and NW. 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.