Report on Kanlaon (Philippines) — 3 March-9 March 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 3 March-9 March 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Kanlaon (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 3 March-9 March 2004. Smithsonian Institution and US Geological Survey.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
On 1 March PHIVOLCS reduced the Alert Level at Canlaon from 1 to 0, due to low seismicity and volcanism. After September 2003, either no activity or weak steam emissions were observed at the summit crater and seismicity was at normal levels. The public was advised that there was still a risk of sudden phreatic explosions occurring in the 4-km Permanent Danger Zone.
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.