COMVOL reported that an average of 60 earthquakes/day were recorded near Canlaon in mid-May, reaching a maximum of 160 on 17 May [but see 5:6]. COMVOL installed three additional seismic stations around the volcano and extended the danger zone from 4 to 10 km. A similar earthquake swarm preceded the 1978 eruption.

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.

Information Contacts: AFP.