Report on Veniaminof (United States) — 21 August-27 August 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 21 August-27 August 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Veniaminof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 21 August-27 August 2019. Smithsonian Institution and US Geological Survey.
56.17°N, 159.38°W; summit elev. 2507 m
All times are local (unless otherwise noted)
AVO lowered the Volcano Alert Level to Normal for Veniaminof and the Aviation Color Code to Green on 25 August, noting that the volcano returned to background activity after low-level tremor was detected and a pilot saw steaming on 1 August.
Geologic Background. Veniaminof, on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700 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.