Report on Kanlaon (Philippines) — May 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 5 (May 1986)
Managing Editor: Lindsay McClelland.
Kanlaon (Philippines) Minor ash ejection
Please cite this report as:
Global Volcanism Program, 1986. Report on Kanlaon (Philippines). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 11:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198605-272020.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
Without any preceding seismic activity, Canlaon weakly ejected ash on 3 June at 0139. Ash reached a height of ~ 300 m above the crater rim before drifting NE. The ejection was accompanied by audible rumbling and an explosion earthquake felt at intensity I, 5.5 km SE of the crater (at Barangay Pula). The event lasted 15 minutes, 45 seconds.
Another explosion earthquake, with 18 mm amplitude, occurred at 0435; it lasted 55 seconds. From 0436 to 0500 there was moderate to voluminous emission of dirty white steam, reaching a height of 300 m and drifting NW. Ash deposits were confined to 200 m from the crater on the SE and NE slopes.
Geologic Background. Kanlaon volcano (also spelled Canlaon), the most active of the central Philippines, forms the highest point on the island of Negros. The massive andesitic stratovolcano is dotted 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, historically active vent, Lugud crater, to the south. Historical eruptions, recorded since 1866, have typically consisted of phreatic explosions of small-to-moderate size that produce minor ashfalls near the volcano.
Information Contacts: PHIVOLCS, Quezon City.