PHIVOLCS reported that unrest at Taal continued during 18-25 January. Low-level background tremor persisted; one volcanic earthquake was recorded during 18-19 January. Hot volcanic fluids were upwelling in the crater lake, and daily gas-and-steam plumes rose 0.6-2.4 km above the lake and drifted SW. Sulfur dioxide emissions continued to be elevated, averaging 10,986 and 11,228 tonnes/day on 20 and 23 January, respectively. 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 is prohibited.

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.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)