Report on Taal (Philippines) — 1 January-7 January 1920
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 1 January-7 January 1920
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 1920. Report on Taal (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 1 January-7 January 1920. Smithsonian Institution and US Geological Survey.
14.002°N, 120.993°E; summit elev. 311 m
All times are local (unless otherwise noted)
A phreatic eruption from a dike intrusion began on 12 January. Activity escalated and a total evacuation of the island and high-risk areas within a 14-km radius began. The eruption plume of steam, gas, and tephra significantly intensified and rose 10-15 km (32,800-49,200 ft) a.s.l., producing frequent lightning. Lava fountaining began the next day; fountains were 500-800 m tall. Ground cracking was observed in areas mainly to the SW. There were a total of 148,987 people in 493 evacuation centers on 21 January; the landscape was eerily gray with tephra deposits which devastated the local residences. In the days following the start of the eruption a fascinating video emerged possibly showing the very start of the eruption.
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.