PHIVOLCS issued a special notice for Kanlaon at 1530 on 30 April noting increased sulfur dioxide emissions. On 30 April a Flyspec instrument measured an average of 2,707 tonnes per day (t/d) of sulfur dioxide emissions at the summit crater, the second highest value recorded in 2024; sulfur dioxide emissions average 3,098 t/d on 19 January. The report noted that higher sulfur dioxide gas fluxes had been recorded for a year with an overall average of 1,300 t/d. The rate of volcanic earthquakes remained at baseline levels of three events per day, though episodes of increased activity had occurred several times during the previous year. 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 1 (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)