The Philippine Institute of Volcanology and Seismology (Phivolcs) raised Bulusan Volcano’s status from Alert Level 0 to Alert Level 1 on Monday following a phreatic eruption that blanketed several Sorsogon communities in ash.
Phivolcs reported that the eruption, which started at 4:36 a.m. and lasted 24 minutes, generated a plume 4,500 meters high that drifted west to southwest. Ashfall was reported in several barangays in Irosin, Juban, and Magallanes towns. A pyroclastic density current descended the southwestern slopes, traveling up to three kilometers from the summit.
Authorities recorded 53 volcanic earthquakes in the 24 hours preceding the eruption. Residents reported rumbling sounds about 15 minutes before the event, confirmed by infrasound sensors.
Phivolcs warned the public against entering the four-kilometer permanent danger zone and advised vigilance within the two-kilometer extended danger zone due to risks of pyroclastic flows, ashfall, and lahars, especially during heavy rains. People were also urged to wear protective masks and avoid inhaling ash. Aircraft were advised to steer clear of the summit area due to the potential hazards of sudden ash emissions.
Following the eruption, the Civil Aviation Authority of the Philippines (CAAP) issued a Notice to Airmen (NOTAM) prohibiting flights near Bulusan up to 21,000 feet. The NOTAM remains in effect until April 29, 2025.
Meanwhile, road clearing operations began in Barangay Buraburan, Juban, where ashfall heavily impacted the national highway. The Sorsogon Provincial Government, supported by the Bureau of Fire Protection, the Philippine National Police, and disaster management officials, mobilized clearing teams. Governor Boboy Hamor urged motorists to avoid the affected roads and called on residents to remain vigilant and follow official advisories.
Bulusan Volcano remains under close monitoring as authorities assess ongoing volcanic activity.