AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 8-15 March, and small explosions were detected in local seismic and infrasound data on most days. Tremor levels was characterized as strong during 8-10 March and moderate during the rest of the week. A satellite image acquired on 7 March showed highly elevated surface temperatures near the vent (likely due to an accumulation of lava spatter), and a dark lahar deposit extending 750 m down the SE flank. Minor ash deposits were visible around the vent. Elevated surface temperatures were visible on most days of the week, though cloud cover sometimes prevented observations, consistent with continued activity. On 14 March satellite images showed minor lava effusion at the vent. 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)