Report on Kanlaon (Philippines) — 30 March-5 April 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
30 March-5 April 2005
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2005. Report on Kanlaon (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 30 March-5 April 2005. Smithsonian Institution and US Geological Survey.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
Ash emissions began from Canlaon on 20 March around 1300. Small amounts of ash fell in the town of Guintubdan 5 km W of the volcano. During 24 March to 4 April, sporadic ash emissions rose to a maximum height of 1 km above the volcano (11,300 ft a.s.l.). During this time ash fell in the towns of La Castellana (16 km SW of the crater), Upper Sag-ang, Yubo (5-6 km SW), and Guintubdan (5-6 km WNW). Due to this low-level episode of unrest, PHIVOLCS raised the Alert Level at Canlaon from 0 to 1 on 30 March. There was also a 4-km-radius Permanent Danger Zone around the volcano's summit. According to a news article, pilots were advised to avoid flying near Canlaon.
Geological Summary. 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.