Report on Veniaminof (United States) — 19 June-25 June 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 19 June-25 June 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Veniaminof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 19 June-25 June 2013. 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 that the eruption of Veniaminof continued during 18-25 June, indicated by volcanic tremor detected by the seismic network. Cloudy weather sometimes prevented views of the caldera, although most days satellite images showed very high elevated surface temperatures at the cinder cone inside the caldera consistent with lava effusion. On 18 June small ash clouds that rose less than 4.6 km (15,000 ft) a.s.l. were intermittently observed in web-camera images. On 24 June satellite images detected elevated surface temperatures and a plume that drifted SW. The web camera recorded a small area of incandescence on the intracaldera cone. On 25 June the web camera showed a light-colored plume rising from the intracaldera cone to just above the caldera rim. The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange.
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 reaches an elevation of 2156 m and 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.