Report on Veniaminof (United States) — 24 April-30 April 2019
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 24 April-30 April 2019
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2019. Report on Veniaminof (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 24 April-30 April 2019. Smithsonian Institution and US Geological Survey.
56.17°N, 159.38°W; summit elev. 2507 m
All times are local (unless otherwise noted)
On 30 April AVO lowered the Aviation Color Code for Veniaminof to Green and the Volcano Alert Level to Normal, noting that signs of unrest had continued to decline over the previous four months since the eruption ended in early January. Low-level tremor, slightly elevated surface temperatures, and minor steam emissions continued and considered typical activity for a post-eruptive period.
Geological Summary. 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.