PHIVOLCS reported ongoing seismic unrest at Taal on 28 August. Ten earthquakes occurred; two at Intensity II were felt by residents in the Pira-Piraso village and were accompanied by rumbling sounds. The earthquakes were located NE of the island near the Daang Kastila area at estimated depths of 0.6-0.8 km. Surface observations indicated no change in the main crater lake area. PHIVOLCS warned that the main crater was off-limits to the general public. The Alert Level remained at 1 (scale is 0-5, 0 referring to No Alert status).

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)