Kanlaon Volcano experienced a minor explosive eruption at 3:11 PM, February 6, 2025, sending ash and sulfurous fumes into the air and triggering lahars in nearby communities, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) said in its advisory.
The eruption, which lasted two minutes according to the Kanlaon Volcano Network’s seismic and infrasound records, produced a plume of ash that rose 600 meters before drifting southwest. Thin ashfall was reported in Sto. Mercedes and San Luis, Brgy. Sag-ang, PHIVOLCS added in its advisory.
The force of the explosion generated an airwave, measured at 70 Pascals five kilometers east of the summit crater. Residents in Brgy. Yubo, La Carlota City, and Brgy. Sag-ang, La Castellana, reported hearing a booming sound, while sulfurous fumes were detected in several barangays of La Castellana. The rainy weather at the time of the eruption led to the immediate formation of syn-eruption lahars in the Buhangin River, which flows through La Castellana and Moises Padilla.
While the eruption followed a period of decreased sulfur dioxide (SO2) flux, measuring an average of 2,249 tonnes/day compared to the medium-term average of 4,484 tonnes/day since June 3, 2024, and weak degassing from the summit crater, volcanic activity has been building.
Inflation or swelling on the upper to middle slopes of the volcano has been observed since January 10, 2025. Experts believe that the pressure build-up caused by occasional plugging of the volcanic conduit, coupled with weakened SO2 emission and degassing, likely triggered the explosion.
Kanlaon Volcano remains under Alert Level 3, indicating magmatic unrest. This means that further short-lived explosive eruptions, potentially generating pyroclastic density currents (PDCs), are possible within the 6-kilometer radius area surrounding the summit. Authorities are urging communities within this zone to evacuate due to the risks of lava flows, rockfalls, PDCs, and other related hazards. Local government units are also preparing for potential further evacuations should the unrest escalate. Residents are advised to remain vigilant against syn-eruption lahars and sediment-laden streamflows, especially during periods of heavy rainfall. Civil aviation authorities have advised pilots to avoid flying near the volcano’s summit due to the potential hazard of ash from sudden eruptions.
