Report on Kanlaon (Philippines) — June 1980
Scientific Event Alert Network Bulletin, vol. 5, no. 6 (June 1980)
Managing Editor: David Squires.
Kanlaon (Philippines) Seismicity declines
Please cite this report as:
Global Volcanism Program, 1980. Report on Kanlaon (Philippines) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 5:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198006-272020.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
An earthquake swarm began 6 May in the vicinity of Canlaon. The number of earthquakes recorded per day on nearby seismographs reached a peak of 108 on 19 May, then seismicity began a gradual decline. In late June, volcanic shocks continued to occur at a rate of about 40/day. As of 27 June, a total of 2,652 events had been recorded. No surface volcanism has been reported with this earthquake swarm.
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: O. Peña, COMVOL, Quezon City.