The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that phreatic eruptive events at Taal periodically continued during 8-15 October. There were 1-2 phreatic events recorded almost daily during the week, with most reportedly lasting 3-13 minutes long. Hot fluids upwelling in the lake were persistently observed, and daily steam-and-gas emissions that were sometime voluminous rose as high as 3 km above the crater rim. Two volcanic earthquakes were detected during 8-9 October, two periods of volcanic tremor lasting two minutes long were recorded during 9-10 October, one volcanic earthquake was recorded during 11-12 October, and a period of tremor lasting 10 hours and 30 minutes was recorded during 12-13 October. Sulfur dioxide emissions averaged 2,256 tonnes per day (t/d) on 9 October, 1,256 t/d on 12 October, and 2,064 t/d/ on 14 October, remaining at elevated levels. Vog was reported during 10-11 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)