Report on Pavlof (United States) — 27 July-2 August 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
27 July-2 August 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, 27 July-2 August 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 26 July-2 August. Daily elevated surface temperatures were identified in satellite images. Seismic tremor persisted and multiple daily explosions were detected in local and regional seismic and infrasound data. The explosions likely produced minor ash emissions that rose no higher than 3 km (10,000 ft) a.s.l., though cloud cover prevented confirmation on most days. Ash emissions were visible in webcam images during 27-28 July. Sulfur dioxide gas emissions were visible on 26 July and team emissions were noted during 30-31 July. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
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.