# Kanlaon eruption pushes Philippine volcano to Alert Level 3 after ash plume and PDCs

An explosive eruption at Kanlaon Volcano on December 9, 2024 pushed Philippine authorities to raise the alert level to 3, intensifying warnings for nearby communities as ashfall, sulfur smell, and fast-moving pyroclastic density currents were reported around the volcano.

The Philippine Institute of Volcanology and Seismology said the eruption began at 3:03 pm Monday and lasted 3 minutes and 55 seconds. It produced a plume that rose about 4 kilometers above the summit vent. PHIVOLCS said the event marked a jump from Alert Level 2, which signals increasing unrest, to Alert Level 3, which indicates magmatic unrest and a higher chance of stronger explosive activity.

The agency said ashfall was reported over a wide area west of the volcano, while the smell of sulfur was detected in barangays in Negros Occidental and as far as the town proper of Bago City. It also said pyroclastic density currents moved down the south-southeastern sides of the edifice, with the longest runout estimated at about 2 to 3.4 kilometers in Barangay Masulog, La Castellana, still inside the 4-kilometer permanent danger zone.

PHIVOLCS chief Maria Antonia Bornas urged residents to treat the hazard as one that cannot be outrun. Her warning focused on avoidance rather than evacuation delays, reflecting the speed and danger of pyroclastic flows. The agency also said a strong pressure wave from the eruption rattled objects within at least a 30-kilometer radius and was recorded by infrasound stations near the crater at levels that could harm hearing.

The eruption was followed by evacuation instructions for local governments within 6 kilometers of the volcano, with PHIVOLCS warning about pyroclastic flows, ballistic projectiles, ashfall, lava flows, rockfalls, and related hazards. The Office of Civil Defense estimated that 87,000 people could be forced to evacuate, with more than half living in La Castellana, Negros Occidental.

Local officials moved quickly to organize responses. La Castellana Mayor Alme Rhummyla Nicor-Mangilimutan activated the local Incident Command System. In nearby Moises Padilla, Mayor Ella Celestina Garcia-Yulo directed disaster personnel to prepare. In Negros Oriental, Canlaon City Mayor Jose Chubasco Cardenas also reactivated emergency coordination efforts.

The alert also reflected concern about secondary hazards if rain reaches the volcano. PHIVOLCS warned that heavy rainfall could generate lahars and sediment-laden streamflows in channels draining the southern flanks. It specifically flagged barangays that had already been hit by pyroclastic flows, along with downstream communities that experienced lahars and muddy streamflows in June 2024.

The eruption came after a day in which PHIVOLCS said sulfur dioxide emissions were noticeably weaker than in previous periods, averaging 1,669 tons per day before the eruption. The agency also reported only six weak volcano-tectonic earthquakes and said no precursory seismic activity preceded the event. Ash samples were collected to help evaluate what triggered the eruption.

Kanlaon straddles Negros Occidental and Negros Oriental and is one of the Philippines’ two dozen active volcanoes. PHIVOLCS said it had erupted more than 40 times since 1866.