Report on Taal (Philippines) — 13 October-19 October 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
13 October-19 October 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Taal (Philippines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 13 October-19 October 2021. Smithsonian Institution and US Geological Survey.
14.002°N, 120.993°E; summit elev. 311 m
All times are local (unless otherwise noted)
PHIVOLCS reported that upwelling of hot volcanic fluids in Taal’s crater lake was visible during 13-18 October, and gas-and-steam plumes rose 1.2-3 km above the lake and drifted in multiple directions. Sulfur dioxide emissions averaged 6,393-12,611 tonnes/day, though on 15 October the emissions peaked at 23,576 tonnes/day, which was the second highest ever sulfur dioxide gas flux recorded at the volcano. Dense vog spread over the Taal Caldera region was noted on 15 October. Earthquake activity resumed on 11 October after a brief lull that first began on 27 September; 145 events characterized as mostly weak low-frequency earthquakes and volcanic tremor were recorded during 11-15 October. Volcanic tremor persisted through 18 October. The Volcano Alert Level remained at a 2 (on a scale of 0-5). PHIVOLCS reminded the public that the entire Taal Volcano Island is a Permanent Danger Zone (PDZ) and that boating on Taal Lake was prohibited.
Geological Summary. 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.