Kanlaon Volcano Registers Brief Ash Emission Under Moderate Unrest Status

The Kanlaon Volcano, an active andesitic stratovolcano located on Negros Island in the Philippines, registered a transient ash emission from its summit crater on Friday, November 21, 2025. The event, monitored by the Philippine Institute of Volcanology and Seismology (PHIVOLCS), lasted only eight minutes before subsiding. The activity produced grayish plumes that rose approximately 75 meters above the crater rim, with dispersal noted toward the west-southwest.

This occurrence takes place while the volcano remains under Alert Level 2, signifying a Moderate Level of Volcanic Unrest on the 0-to-5 scale. PHIVOLCS Director Teresito Bacolcol has previously stated that such ash emissions are an anticipated consequence of the volcano experiencing a fresh release of volcanic gas and associated pressure within its system. This degassing process is responsible for bringing fine, dry materials, or ash, accumulated in the crater to the surface.

Kanlaon, which stands as the highest peak on Negros Island and in the Visayas region at an elevation of 2,465 meters, has a documented history of intermittent activity. PHIVOLCS reported continuing eruptive activity between November 19 and November 25, which included daily volcanic earthquakes and significant sulfur dioxide emissions ranging between 5,125 to 8,040 tonnes per day. This pattern follows a more substantial explosive eruption on October 24, 2025, which generated a plume reaching 2,000 meters high.

The ongoing Alert Level 2 status mandates precautionary measures for the surrounding population and aviation. Authorities advise the public to strictly avoid the four-kilometer radius designated as the Permanent Danger Zone (PDZ) due to the inherent risks of sudden steam-driven or phreatic eruptions, rockfalls, and potential pyroclastic density currents. Civil aviation bodies are cautioned against operating aircraft near the summit, as airborne ash poses a tangible hazard to flight operations.

Local government units in Negros Occidental and Negros Oriental provinces are urged to maintain preparedness for potential evacuation scenarios, particularly as heavy rainfall could trigger lahars or sediment-laden streamflows in adjacent river systems. The monitoring efforts by PHIVOLCS, utilizing data from instruments like the Kanlaon Volcano Observatory–Canlaon City IP camera, remain critical for assessing the evolving volcanic hazard profile of the structure, which is part of the Negros Volcanic Belt.