Report on Kanlaon (Philippines) — 30 January-5 February 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 30 January-5 February 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Kanlaon (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 30 January-5 February 2002. Smithsonian Institution and US Geological Survey.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
During early February, high-frequency earthquakes were recorded at Canlaon at depths of 1-5.5 km. In the previous week, several low-frequency earthquakes were recorded. According to a news report, PHIVOLCS stated that the occurrence of low-frequency earthquakes supports the idea that some fluid migration, possibly magma ascent, is occurring. The Alert Level remained at 1 ("Low-level unrest"), and a 4-km-radius Permanent Danger Zone was in effect.
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.
Source: Sun Star News