Report on Taal (Philippines) — December 1976
Natural Science Event Bulletin, vol. 1, no. 15 (December 1976)
Managing Editor: David Squires.
Taal (Philippines) Weak steaming; larger steam plume on 30 October
Please cite this report as:
Global Volcanism Program, 1976. Report on Taal (Philippines) (Squires, D., ed.). Natural Science Event Bulletin, 1:15. Smithsonian Institution.
14.002°N, 120.993°E; summit elev. 311 m
All times are local (unless otherwise noted)
By 30 October, Taal's eruption had declined to weak steaming, and harmonic tremor had ended. Harmonic tremor resumed at 1925 on 30 October and steam eruptions began at about 2130. During the early morning of 31 October, cauliflower-shaped steam clouds reaching 100 m height were observed, containing only minimal amounts of ash. This activity continued through the day, the clouds gradually decreasing in height and volume. No further activity had been reported by 16 November.
Further References. Alcaraz, A., and Datuin, R., 1977, Notes on Taal volcano prognostics: Journal of the Geological Society of the Philippines, v. 31, no. 2, p. 18-20.
Andal, G.A., and Aguila, L.G., 1977, Prognostic criteria of the 1976 eruption of Taal volcano: COMVOL Letter, v. 9, no. 1-2, p. 1-6.
Geologic Background. Taal is one of the most active volcanoes in the Philippines and has produced some of its most powerful historical eruptions. Though not topographically prominent, its prehistorical eruptions have greatly changed the landscape of SW Luzon. 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, and several eruptive centers lie submerged beneath the lake. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all historical eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones that have grown about 25% in area during historical time. Powerful pyroclastic flows and surges from historical eruptions have caused many fatalities.
Information Contacts: Manila Times-Journal.