Report on Pavlof (United States) — 16 October-22 October 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 16 October-22 October 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Pavlof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 16 October-22 October 2019. Smithsonian Institution and US Geological Survey.
55.417°N, 161.894°W; summit elev. 2493 m
All times are local (unless otherwise noted)
On 19 October small explosion signals at Pavlof were detected by the infrasound network located at Sand Point and on the local seismic network, prompting AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. Clouds obscured satellite views of the volcano around the time of the event; slightly elevated surface temperatures were detected in satellite images during 19-20 October.
Geologic Background. 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.