Report on Kanlaon (Philippines) — 9 December-15 December 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 December-15 December 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Kanlaon (Philippines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 9 December-15 December 2015. Smithsonian Institution and US Geological Survey.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
PHIVOLCS reported that two volcanic earthquakes at Kanlaon were accompanied by a one-minute, low-energy, gray ash emission at 0513 on 11 December. Observers noted ash emissions at 0951, 1008, 1140, and 0101 on 13 December which rose 200-300 m and drifted SW. The emissions were not detected by the seismic network, indicating a shallow source. Trace amounts of ashfall were reported in Sitio Bais, Brgy Yubo, and La Carlota City on the W flank and Brgy Sag-ang and La Castellana on the SW flank. The Alert Level remained at 1 (on a scale of 0-5).
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.