Report on Pavlof (United States) — 9 March-15 March 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
9 March-15 March 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, 9 March-15 March 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 the eruption at a vent on Pavlof’s upper E flank was ongoing during 8-15 March, and small explosions were detected in local seismic and infrasound data on most days. Tremor levels was characterized as strong during 8-10 March and moderate during the rest of the week. A satellite image acquired on 7 March showed highly elevated surface temperatures near the vent (likely due to an accumulation of lava spatter), and a dark lahar deposit extending 750 m down the SE flank. Minor ash deposits were visible around the vent. Elevated surface temperatures were visible on most days of the week, though cloud cover sometimes prevented observations, consistent with continued activity. On 14 March satellite images showed minor lava effusion at the 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.