PHIVOLCS reported that during 20-25 July diffuse white plumes rose above Kanlaon; On 20 July plumes were a dirty-white color, and on 25 July they rose 200 m and drifted NW and SW. The Alert Level remained at 1 (on a scale of 0-5).

Geological Summary. Kanlaon volcano (also spelled Canlaon), the most active of the central Philippines, forms the highest point on the island of Negros. The massive andesitic stratovolcano is dotted 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, historically active vent, Lugud crater, to the south. Historical eruptions, recorded since 1866, have typically consisted of phreatic explosions of small-to-moderate size that produce minor ashfalls near the volcano.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)