Report on Pavlof (United States) — October 1975
Natural Science Event Bulletin, vol. 1, no. 1 (October 1975)
Managing Editor: David Squires
Pavlof (United States) Columns of "smoke" to 2,400 m
Please cite this report as:
Global Volcanism Program, 1975. Report on Pavlof (United States). In: Squires, D (ed.), Natural Science Event Bulletin, 1:1. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.NSEB197510-312030.
55.417°N, 161.894°W; summit elev. 2493 m
All times are local (unless otherwise noted)
For the past several weeks Pavlof has been producing columns 2,100-2,400 m high, carried NE up the Alaska Peninsula. Weather conditions commonly prevent observation of the volcano, but on 26 October it was active for 30 minutes of the hour that it was visible. On 31 October, for 1.5 hours, "lava" was reported streaming down the N side of the cone; this may have been a mud flow.
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: P. Sventek, USAF, Cold Bay.