NEGROS ISLAND, Philippines — The Philippine Institute of Volcanology and Seismology (PHIVOLCS) issued a warning following a sharp rise in volcano-tectonic (VT) quakes and persistent, thick degassing at Kanlaon Volcano on Thursday, October 1.
Between midnight and 5:00 p.m. on Thursday, the agency detected 28 VT earthquakes ranging from magnitude 0.9 to 1.8, positioned at depths up to 11 kilometers beneath the volcano’s western slopes.
“VTs are generated by rock-fracturing processes and the increase in VT activity strongly indicates progressive rock-fracturing beneath the volcano as rising magma or magmatic gas drives a path towards the surface,” PHIVOLCS said.
Additionally, a dense gas plume was seen rising from the crater starting Thursday noon. Sulfur dioxide output averaged 1,819 tons daily on September 30, up from the 1,578-ton daily average recorded since January 1, 2026.
“These parameters indicate that significant volcanic gas at depth may be forcing its way up the edifice and inducing VT earthquake activity at depth and increased plume activity at the summit crater,” it said.
Volcanic unrest intensified further into Friday, October 2, with the 5:00 a.m. 24-hour monitoring bulletin recording 94 volcanic quakes, sulfur dioxide emissions reaching 1,955 tons per day, and gas plumes climbing 1.3 kilometers above the peak.
Alert Level 2 remains in place over Kanlaon, signaling a state of heightened unrest.
PHIVOLCS noted that the surge in VT tremors and gas discharge “could lead to increased chances of steam-driven or phreatic eruptions or short-lived weak to moderately explosive eruptions occurring at the summit.”
The agency cautioned that such events could trigger dangerous volcanic threats, including pyroclastic density currents (PDCs), ballistic rocks, ashfall, and rockfalls.
Residents inside the 4-kilometer permanent danger zone (PDZ) are urged to stay evacuated, while those within a 6-kilometer radius are advised to remain alert. PHIVOLCS also warned of potential lahars during heavy rains and urged aviation authorities to keep aircraft clear of the summit area.