The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 25 February-3 March. The seismic network recorded 3-10 daily volcanic earthquakes, though on 28 February there were 24 volcanic earthquakes along with three periods of volcanic tremor lasting from three minutes to two hours and 13 minutes. Average daily sulfur dioxide emissions ranged from 1,118 to 2,527 tonnes per day. Gas-and-steam emissions that were sometimes diffuse rose generally as high as 100 m above the summit and drifted W, SW, and SSW; weather conditions obscured views during 2-3 March. On 28 February three periods of ash emissions corresponding to the periods of volcanic tremor produced gas-and-ash plumes that rose as high as 150 m above the summit and drifted SW and WSW. According to the Office of Civil Defense and news reports more than 8,500 people remained in evacuation shelters, noting that 36 families from La Castellana (16 km SW) and 48 families from Canlaon City (10 km ESE) will not be able to return to their homes within the 4-km permanent danger zone. 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.

Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Office of Civil Defense, Inquirer.net