Manila: The Philippine Institute of Volcanology and Seismology (Phivolcs) lowered the status of Kanlaon Volcano from Alert Level 3 (magmatic unrest / high level of volcanic unrest) to Alert Level 2 (moderate level of volcanic unrest). "Kanlaon Volcano has been exhibiting less frequent volcanic earthquake activity, decreased volcanic gas emitted by subsurface magma and ground deformation cycles," Phivolcs said in an advisory Tuesday night. Kanlaon's last eruptive activity was on May 13.
According to Philippines News Agency, an average of eight volcanic earthquakes per day was recorded from May 14 to July 29. This indicates a significant decrease from the medium-term average of 14 volcanic earthquakes per day from June 3, 2024, to May 13, 2025, Phivolcs said. Volcano-tectonic earthquakes generated by rock fracturing within the edifice continue to dominate earthquake activity at Kanlaon. Ash emission from the summit crater, which began in October 2024, has ceased after the last event on June 5, 2025. "Since then, activity at the crater has transitioned to quiet degassing of steam-dominated plumes," the advisory read.
Sulfur dioxide flux also declined to an average of 1,857 tonnes/day from May 13 to July 29. "Decreased degassing at Kanlaon could indicate a pause in the intrusion of, or depletion of volcanic gas in, magma within the shallower levels of the edifice, or the sealing of magmatic gas pathways," Phivolcs said. Meanwhile, Phivolcs said Alert Level 2 should not be interpreted that unrest has ceased or that the threat of an eruption has disappeared, given that magma has already been intruded deep beneath the edifice.
At Alert Level 2, communities within the 4-km. radius permanent danger zone should remain evacuated due to the lingering chances of short-lived explosive eruptions and sudden steam-driven or phreatic explosions that can generate life-threatening volcanic hazards such as pyroclastic density currents (PDCs), ballistic projectiles, rockfalls, and lethal expulsions of volcanic gas. Local government units are urged to continue preparing their communities within the PDC hazard zone for subsequent evacuation in case unrest re-escalates and progresses into a magmatic eruption.
Increased vigilance against potential lahars and sediment-laden streamflows in channels draining the volcanic slopes must continually be exercised in case eruptive unrest resumes under heavy to intense rainfall, Phivolcs added. Aviation authorities must advise pilots to avoid flying close to the volcano's summit as ash from any sudden eruption can be hazardous to aircraft, Phivolcs said.
