The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 22-28 April. The seismic network recorded 7-36 daily volcanic earthquakes and one period of volcanic tremor (10 minutes long) on 28 April. Daily sulfur dioxide emissions ranged from 1,693 to 2,736 tonnes per day. Gas-and-steam emissions generally rose 150-400 m above the crater rim and drifted WNW, W, and SW. There was one ash emission on 28 April that lasted 10 minutes long based on the seismic signal. The ash-and-gas plume rose 200 m and drifted SW. The Alert Level remained at 3 (on a scale of 0-5); the public was warned to stay 6 km away from the summit and pilots were warned 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)