Report on Pavlof (United States) — 29 December-4 January 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
29 December-4 January 2022
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Pavlof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 29 December-4 January 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 seismicity at Pavlof was elevated during 29 December 2021 to 4 January 2022 and was characterized by daily periods of tremor. Minor ash emissions were visible during 28-29 December and small explosions were occasionally recorded during 29-30 December. Thermal emissions continued to be low, and elevated surface temperatures consistent with a hot vent region were identified in satellite images during 1-3 January. During 3-4 January lava was active in an area within 100 m of the SE vent. 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.