Report on Taal (Philippines) — October 1989
Scientific Event Alert Network Bulletin, vol. 14, no. 10 (October 1989)
Managing Editor: Lindsay McClelland.
Taal (Philippines) Increased seismicity; main crater inflation
Please cite this report as:
Global Volcanism Program, 1989. Report on Taal (Philippines) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 14:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198910-273070
14.0106°N, 120.9975°E; summit elev. 311 m
All times are local (unless otherwise noted)
Since July, seismicity at Taal has increased from background level to a maximum of 126 volcanic earthquakes/week, with at least three events recorded daily. Epicenters clustered around the main crater and about 2 km NE (near Pinagulbuan), migrating from 9 to 5 km depth, 18 August-2 October. Precise leveling and dry tilt surveys suggest inflation of the main crater and the 1965 eruption site, while a water tube tiltmeter has measured inflation of the main crater area since May.
Geological Summary. Taal is one of the most active volcanoes in the Philippines and has produced some powerful eruptions. The 15 x 20 km Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2 surface lies only 3 m above sea level. The maximum depth of the lake is 160 m, with several submerged eruptive centers. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all observed eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows and surges have caused many fatalities.
Information Contacts: PHIVOLCS.