AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 22-29 March, and seismic tremor persisted. Elevated surface temperatures were identified in satellite images on most of the days and were consistent with minor lava effusion. Cloud cover sometimes prevented webcam and satellite views of the summit area; sulfur dioxide emissions were visible in satellite images during 24-26 March. Two small explosions were detected in local and regional infrasound data during 23-24 March and one was recorded during 26-27 March. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

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)