The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported eruptive activity at Taal during 9-16 September. The seismic network recorded 1-9 daily periods of volcanic tremor ranging from two minutes up to almost 29 hours. There were 5-10 daily volcanic earthquakes that included the volcanic tremor signals during 9-13 September, though no volcanic earthquakes were recorded on 14 September. Daily gas-and-steam emissions with variable densities rose 600-1,200 m above the crater rim and drifted SW. Sulfur dioxide emissions averaged 1,749 tonnes per day (t/d) on 9 September and 1,456 t/d on 11 September. One minor phreatic event occurred on 11 September and lasted for two minutes. Volcano Island (TVI) was a Permanent Danger Zone (PDZ) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain prohibited. Pilots were warned to avoid flying over TVI.

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)