PHIVOLCS reported continuing unrest at Taal during 26 June-4 July. Daily white steam-and-gas plumes, voluminous during the first half of the week, rose as high as 2.4 km above the lake and drifted NE, NW, S, and SW; voggy conditions were reported during 2-3 July. Upwelling gasses and hot fluids in the lake were periodically visible. Sulfur dioxide emissions were variable, averaging 7,480 (28 June), 1,165 (30 June), and 4,472 (3 July) tonnes per day. Two periods of volcanic tremor, each lasting 2-3 minutes long, and three volcanic earthquakes were recorded during 26-29 June. There were 9-11 daily volcanic earthquakes recorded during 29 June-2 July, including 1-8 periods of volcanic tremor, each lasting 1-14 minutes. One volcanic earthquake was recorded during 2-3 July. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ).

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)