The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing unrest at Kanlaon during 16-22 October, characterized by elevated seismicity and sulfur dioxide emissions. Visual monitors recorded continuous degassing, with brief episodes when gray ash was entrained in the plume. Three “ashing” events, at 0641, 0701, and 0801 on 19 October, lasted two to six minutes long, based on visual observations; no detectable seismic or infrasound signals were recorded. The events generated light-gray plumes that rose 500 m above the crater and drifted SW. Traces of ash deposits were reported in the barangays of Yubo and Ara-al, La Carlota City (14 km W), and Sag-ang, La Castellana (16 km SW). A sulfur dioxide odor was also reported in Yubo.

The seismic network recorded 6-19 daily volcanic earthquakes. Daily gas-and-steam emissions that were sometimes voluminous rose 200-900 m above the summit and drifted W, SW, S, and SE. Sulfur dioxide emissions were recorded during 16-20 October and continued to be high, averaging 2,679-6,477 tonnes/day. 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 and warned pilots not to fly close to the volcano.

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)