Report on Sheveluch (Russia) — 5 July-11 July 2023
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 5 July-11 July 2023
Managing Editor: Sally Sennert. Written by Zachary W. Hastings.
Please cite this report as:
Global Volcanism Program, 2023. Report on Sheveluch (Russia) (Hastings, Z W, and Sennert, S, eds.). Weekly Volcanic Activity Report, 5 July-11 July 2023. Smithsonian Institution and US Geological Survey.
56.653°N, 161.36°E; summit elev. 3283 m
All times are local (unless otherwise noted)
KVERT reported that eruptive activity continued at Sheveluch during 29 June-6 July. Daily thermal anomalies were observed in satellite images and intense fumarolic activity was visible from both the active crater and lava dome. An aviation notice on 2 July described a gas-and-steam plume with some ash that rose 3.5 km a.s.l. and drifted 39 km W. Additional aviation notices caused by resuspended ash were issued on 30 June and 1, 4, and 5 July; plumes rose up to 3 km a.s.l. and drifted as far as 95 km ESE, SE, W, and WNW. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Geological Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.