Report on Veniaminof (United States) — 27 February-4 March 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 27 February-4 March 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Veniaminof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 27 February-4 March 2008. Smithsonian Institution and US Geological Survey.
56.17°N, 159.38°W; summit elev. 2507 m
All times are local (unless otherwise noted)
AVO reported elevated seismic activity from Veniaminof during 27 February-4 March. Web camera views showed steaming from the cone and occasional small ash bursts that rose to 200 m above the crater on 27 February. During 28 February-3 March views were obscured by cloud cover; low-level steaming was seen on 29 February during a break in the weather.
Geologic Background. Massive Veniaminof volcano, one of the highest and largest volcanoes on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3700 years ago. The caldera rim is up to 520 m high on the north, is deeply notched on the west by Cone Glacier, and is covered by an ice sheet on the south. Post-caldera vents are located along a NW-SE zone bisecting the caldera that extends 55 km from near the Bering Sea coast, across the caldera, and down the Pacific flank. Historical eruptions probably all originated from the westernmost and most prominent of two intra-caldera cones, which rises about 300 m above the surrounding icefield. The other cone is larger, and has a summit crater or caldera that may reach 2.5 km in diameter, but is more subdued and barely rises above the glacier surface.