PHIVOLCS Monitors Increased Activity in Kanlaon and Bulusan Volcanoes; Public Urged to Stay Alert

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) has issued separate advisories for Kanlaon Volcano in Negros Island and Bulusan Volcano in Sorsogon, warning the public of heightened volcanic activity and urging continued vigilance amid possible hazards.

On Saturday morning (October 12, 2025), Kanlaon Volcano generated grayish ash plumes that rose approximately 300 meters above its summit crater, as recorded by the Kanlaon Volcano Observatory in Canlaon City (KVO-CC). The ash clouds drifted southeast following the brief emission.

PHIVOLCS said Alert Level 2 (Increased Unrest) remains in effect over Kanlaon, indicating probable magma intrusion at shallow depths, which could lead to phreatic or magmatic eruptions.

Communities around the volcano are strongly advised to avoid the four-kilometer Permanent Danger Zone (PDZ)due to the risks of sudden explosions, rockfall, and volcanic gas emissions. Civil aviation authorities have likewise been urged to restrict flights near the summit, as airborne ash may pose hazards to aircraft.

Meanwhile, Bulusan Volcano in Sorsogon Province has also exhibited signs of unrest, with 72 volcanic earthquakesdetected by the Bulusan Volcano Network (BVN) since midnight of October 11. These volcano-tectonic (VT) earthquakes, associated with rock fracturing, were recorded at depths of less than 10 kilometers beneath the volcano’s northern sector.

PHIVOLCS reported that degassing activity from active vents has remained weak in recent days, while sulfur dioxide (SO₂) emissions measured on October 9 averaged 31 tonnes per day, still below the baseline of 200 tonnes per day. Despite the uptick in seismicity, Alert Level 1 (Low-Level Unrest) remains in effect over Bulusan.

However, the agency warned that sudden steam-driven or phreatic eruptions may occur without warning. Entry into the 4-kilometer PDZ is strictly prohibited, and vigilance within the 2-kilometer Extended Danger Zone (EDZ), particularly on the volcano’s southeast sector, is strongly advised.

Residents are reminded to take precautions against ashfall, including wearing protective masks or damp cloths, especially for vulnerable individuals such as the elderly, pregnant women, infants, and those with respiratory conditions.

PHIVOLCS also cautioned communities along valleys and river channels, particularly on Bulusan’s western slopes, to stay alert for sediment-laden streamflows or lahars that could occur during heavy rainfall.

As volcanic activities intensify in the Visayas and Bicol regions, PHIVOLCS continues to closely monitor both volcanoes and coordinate with local government units to ensure public safety, preparedness, and timely information dissemination.