Report on Taal (Philippines) — July 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 7 (July 1991)
Managing Editor: Lindsay McClelland.
Taal (Philippines) Abnormal seismicity continues
Please cite this report as:
Global Volcanism Program, 1991. Report on Taal (Philippines) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 16:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199107-273070.
14.002°N, 120.993°E; summit elev. 311 m
All times are local (unless otherwise noted)
Abnormally high levels of seismicity continued as of mid-August. Up to 5 small high-frequency earthquakes were recorded daily 9-12 August. No earthquakes were felt during this time. The main crater lake temperature remained at 31°C. Close monitoring of the volcano continued.
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: R. Punongbayan, PHIVOLCS.