Report on Pavlof (United States) — 23 November-29 November 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
23 November-29 November 2022
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2022. Report on Pavlof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 November-29 November 2022. Smithsonian Institution and US Geological Survey.
55.417°N, 161.894°W; summit elev. 2493 m
All times are local (unless otherwise noted)
AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 23-29 November and nearly continuous seismic tremor was recorded. Vent incandescence was visible in webcam images on most days, suggesting ongoing lava effusion. Elevated surface temperatures were occasionally identified in satellite images. Minor ash emissions were observed in webcam images during 26-27 November. A seismic signal at 1748 on 28 November indicated a flowage event. Webcam images from 29 November confirmed that a flowage event had occurred, and a resulting gas cloud possibly containing ash rose as high as 6.1 km (20,000 ft) a.s.l. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Geological Summary. The most active volcano of the Aleutian arc, Pavlof is a 2519-m-high Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and its twin volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, Pavlof has been frequently active in historical time, typically producing Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest historical eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows.