The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported eruptive activity at Taal during 16-22 July. On 15 July the seismic network recorded two volcanic earthquakes including one period of volcanic tremor lasting five minutes. Sulfur dioxide emissions averaged 504 tonnes per day. Gas-and-steam emissions rose 600 m above the crater rim and drifted ENE. No earthquakes were recorded on 16 July. Gas-and-steam emissions rose 400 m above the crater rim and drifted NE. A series of three phreatomagmatic events occurred during 1501-1513 on 17 July. Dark material was ejected above the crater rim and a voluminous eruption plume rose 2.4 km and drifted SE. Strong tremor preceded the eruption. 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)