The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that unrest at Taal continued during 22-29 October. Two phreatic events lasting 5-9 minutes long were recorded on 22 October. Hot fluids upwelling in the lake were observed and steam-and-gas plumes rose 1.5 km above the crater rim and drifted SE. Upwelling of hot fluids was again observed on 23 October; weather conditions often obscured views during 23-25 October. Four-minute-long tremor signals were recorded on 24 and 27 October. Steam-and-gas plumes rose 300-900 m and drifted NNE and NE during 26-27 October. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain 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)