Report on Pavlof (United States) — 5 October-11 October 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
5 October-11 October 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, 5 October-11 October 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 4-11 October. Seismic tremor continued. Strongly elevated surface temperatures were identified in satellite images during 5-6 October and incandescence was visible in nighttime webcam images. Discolored snow near the vent was visible in webcam views during the morning of 7 October suggesting low-level explosive activity; a small explosion was recorded at 1503 that same day though cloudy conditions prevented visual confirmation. Two small explosions were detected during 8-11 October. Very small ash emissions and lava near the vent were visible in occasional clear webcam images during 10-11 October. 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.
Source: US Geological Survey Alaska Volcano Observatory (AVO)