Report on Pavlof (United States) — 19 November-25 November 2014

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 19 November-25 November 2014
Managing Editor: Sally Kuhn Sennert

Please cite this report as:

Global Volcanism Program, 2014. Report on Pavlof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 19 November-25 November 2014. Smithsonian Institution and US Geological Survey.

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Pavlof

United States

55.417°N, 161.894°W; summit elev. 2493 m

All times are local (unless otherwise noted)


AVO reported that seismic activity at Pavlof decreased during 21-22 November but continued to remain above background levels. Weakly elevated surface temperatures during 22 and 24-25 November, consistent with the cooling lava flow on the NW flank, were observed in satellite images. The Aviation Color Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory on 25 November; AVO noted that seismicity was at low levels during the previous week, and satellite observations show no evidence for continuing eruptive activity.

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.

Source: US Geological Survey Alaska Volcano Observatory (AVO)