PHIVOLCS reported that at Taal during 16-23 March there were 36-193 daily volcanic earthquakes and 27-156 daily periods of volcanic tremor with variable durations (1-15 minutes). Three hybrid earthquakes were recorded each day on 18 and 19 March. Diffuse steam plumes from fumarolic vents in Main Crater rose as high as 100 m. Daily measurements of sulfur dioxide emissions were 603-1,184 tonnes per day. The Alert Level remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater and Daang Kastila fissure (along the walking trail) was strictly prohibited.

Geological Summary. Taal is one of the most active volcanoes in the Philippines and has produced some of its most powerful historical eruptions. Though not topographically prominent, its prehistorical eruptions have greatly changed the landscape of SW Luzon. 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, and several eruptive centers lie submerged beneath the lake. 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)