Report on Kanlaon (Philippines) — 15 June-21 June 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 June-21 June 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Kanlaon (Philippines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 15 June-21 June 2016. Smithsonian Institution and US Geological Survey.
10.412°N, 123.132°E; summit elev. 2435 m
All times are local (unless otherwise noted)
Based on visual observations, PHIVOLCS reported that a series of three eruptive events occurred at Kanlaon on 18 June, beginning at 0919 and lasting 27 minutes. These events were recorded by the seismic monitoring network as consecutive explosion-type earthquakes that lasted 30, 42, and 29 seconds, respectively. The first event, a steam-and-gas explosion, generated a light gray-to-white ash plume that rose 1.5 km above the crater and then later to 3 km. The second event, an ash eruption immediately following the first event, produced a dense black ash plume that rose 500 m. Lastly, a grayish ash plume rose 500 m. Minor ashfall was reported to the W in the barangays of Ara-al, San Miguel, and Yubo in La Carlota City (14 km W), Sag-ang in La Castellana (16 km SW), and Ilijan in Bago City (30 km NW). A diffuse sulfur odor was detected in Ara-al. 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.