Report on Pavlof (United States) — 15 May-21 May 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
15 May-21 May 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, 15 May-21 May 2019. 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 low-frequency tremor was detected at Pavlof during 14-15 May and a vigorous steam plume rising from the summit was visible in webcam images on 15 May. The Aviation Color Code was raised to Yellow and the Volcano Alert Level was raised to Advisory primarily because of increased seismicity. Steam plumes recorded by the webcam, low levels of seismic tremor, and warm surface temperatures identified in satellite data continued during 16-19 May; AVO noted that steam emissions and warm surface temperatures are common at Pavlof.
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.