PHIVOLCS reported that hot volcanic fluids circulated and upwelled in Taal’s Main Crater lake during 30 March through 6 April, producing plumes that rose as high as 2 km above the lake’s surface and drifted SW. Sulfur dioxide emissions averaged 265-7,856 tonnes/day during the week. Tremor events persisted daily until 5 April. Three phreatomagmatic bursts from the Main Crater were detected at 1039, 1047, and 1055 on 1 April, based on seismic data and webcam images, which produced plumes 500-900 m tall that drifted SW. PHIVOLCS noted that Alert Level 3 (magmatic unrest) means that there has been a magmatic intrusion and evacuation of high-risk barangays is recommended.

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)