AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 16-22 November and nearly continuous seismic tremor was recorded. Almost daily elevated surface temperatures were identified in satellite images; weather clouds prevented views during 21-22 November. Webcam images showed occasional minor steaming and minor ash emissions in addition to a recent mass flow and ash deposits on the upper to lower flanks visible during 15-16 November, and incandescence at the vent during 16-17 November possibly associated with lava spattering or fountaining. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Geological Summary. The most active volcano of the Aleutian arc, Pavlof is a Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and Pavlof Sister to the NE form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that overlook Pavlof and Volcano bays. Little Pavlof is a smaller cone on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, eruptions have frequently been reported from Pavlof, typically 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 recorded 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)