PHIVOLCS reported that unrest at Taal continued during 15-22 June. Low-level background tremor that had begun at 0905 on 8 April continued. One volcanic earthquake was recorded during 15-16 June, and 92 were recorded during 18-19 June along with 10 low-frequency volcanic earthquakes. Between two and 82 episodes of volcanic tremor were detected during 18-19, 19-20, and 21-22 June, with periods lasting as short as one minute to as long as four hours. Almost daily upwelling of hot volcanic fluids in the crater lake produced steam plumes that rose as high as 1.2 km and drifted in multiple directions. Sulfur dioxide emissions averaged 3,007-5,604 tonnes/day. PHIVOLCS noted the continuing state of elevated unrest, reminding the public that the Alert Level for Taal remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater, Daang Kastila fissure (along the walking trail), and boating on Taal Lake was strictly prohibited.

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)