PHIVOLCS reported that an approximately 10-minute-long, low-energy phreatic eruption at Kanlaon began at 0947 on 9 December. A plume of voluminous steam and dark ash rose 3-4 km above the summit vent. The event was heard as far away as La Castellana, Negros Occidental. Minor amounts of ash fell in Sitio Guintubdan, and barangays Ara-al, Sag-ang, and Ilihan. The eruption was preceded by the resumption of degassing at the summit crater at 0634, detectable as continuous low-energy tremor during periods when the summit was not visible; degassing was last observed September 2016. The Alert Level remained at 2 (on a scale of 0-5).

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)