PHIVOLCS issued a special notice for Kanlaon at 2330 on 10 August noting increased sulfur dioxide emissions. Earlier in the day a Flyspec instrument measured an average of 4,839 tonnes per day (t/d) of sulfur dioxide emissions at the summit crater, the third highest value recorded in 2024. Gas emissions rose 400-600 m above the carter rim and drifted SE and NE during 10-13 August. Another special notice was issued at 1830 on 13 August noting that the Flyspec instrument measured an average of 7,307 t/d, the highest sulfur dioxide emissions ever recorded at the volcano. Higher sulfur dioxide gas fluxes had been recorded in 2024 with an average of 1,273 t/d prior to the 3 June eruption; afterward the eruption emissions were elevated, averaging 3,102 t/d. An average of nine volcanic earthquakes per day also persisted after the 3 June eruption. Ground deformation data from continuous GPS and electronic tilt data indicated inflation of the volcano since March 2022 and specifically at the E flank starting in 2023. The Alert Level remained at 2 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone.

Geological Summary. Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)