Report on Pavlof (United States) — February 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 2 (February 1988)
Managing Editor: Lindsay McClelland.
Pavlof (United States) Weak steam and ash emission
Please cite this report as:
Global Volcanism Program, 1988. Report on Pavlof (United States). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 13:2. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198802-312030.
55.417°N, 161.894°W; summit elev. 2493 m
All times are local (unless otherwise noted)
During observations that were limited by poor weather December-February, only weak steam and ash emission was reported (table 5).
Table 5. Reports of activity at Pavlof, 9 January-2 March 1988, compiled by John Reeder from the following observers (initials in brackets): Theresa Dubber, James Yakal, and Marsha Brown (FAA, Cold Bay); Guy Morgan (Peninsula Airways).[Skip text table]
Date Time Activity Reported [Observers] 09 Jan 1530 150-m steam plume with some ash from NE summit vent. [TD] 28 Feb 0845 Black plume several hundred meters high from NE summit vent; 15 minutes later, a steam-and-ash plume was rising 600 m and drifting a short distance E. [JY & MB] 02 Mar 1200 Gray steam-and-ash plume rising 300-450 m from NE summit vent and drifting E. Only white steam was visible by 1630 and there were no emissions by 1819. The volcano was snow-covered except for snow-free areas around the summit and NE vents. [GM & MB]
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.