Report on Pavlof (United States) — September 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 9 (September 1987)
Managing Editor: Lindsay McClelland.
Pavlof (United States) New ash deposit
Please cite this report as:
Global Volcanism Program, 1987. Report on Pavlof (United States). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 12:9. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198709-312030.
55.417°N, 161.894°W; summit elev. 2493 m
All times are local (unless otherwise noted)
Marsha Brown (FAA, Cold Bay) observed "fairly extensive" black ash deposits on Pavlof's flanks during a flight on 4 September. Both the NE and SE summit-area vents were emitting steam. The ash deposits had not been visible when the volcano was observed on 30 August. On 20 September the volcano was inactive and fresh snow covered the flanks.
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.
Information Contacts: J. Reeder, ADGGS.