The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported eruptive activity at Taal during 3-9 December. The seismic network recorded 3-9 daily volcanic earthquakes along with periods of volcanic tremor lasting one minute long to over 13 hours long. Daily gas-and-steam emissions with variable densities generally rose as high as 600 m above the crater rim and drifted mainly SW and NE. Minor phreatic and phreatomagmatic events at 0058 and 0104 on 4 December produced plumes that rose 1.2 km above the crater rim and drifted SW. Both events lasted two minutes. The second event ejected incandescent ballistics 300 m above the lake. Sulfur dioxide emissions averaged 466 tonnes per day on 5 December. The Alert Level remained at 1 (on a scale of 0-5); PHIVOLCS reminded the public that the entire Taal 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)