PHIVOLCS issued a special notice for Kanlaon at 1400 on 3 July, noting increased earthquake activity beneath the summit. A total of 41 volcanic earthquakes were recorded by the seismic network beginning at 0500 on 30 June, including seven shallow tornillo signals indicating gas movement through fractures in the upper flanks. Ground deformation data from continuous GPS indicated minor, short-term inflation of the lower and mid-flanks of the volcano since January 2022, consistent with continuous electronic tilt data that had recorded inflation on the SE flanks since mid-March 2022. The seismicity and inflation likely reflected shallow hydrothermal processes. 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)