PHIVOLCS lowered the Alert Level for Taal to 1 (on a scale of 0-5) on 11 July, noting that during the previous two months activity was characterized by baseline levels of volcanic earthquakes, weak gas emissions, and minor surface activity. Phreatomagmatic bursts from Main Crater were last observed on 2 and 10 February and 26 March. An average of seven daily volcanic earthquakes were recorded during 1 January-31 May, and none were detected after 13 June. Deformation data since January 2020 showed overall deflation. Sulfur dioxide emissions averaged 1,214 tonnes per day during May-July, though the most recent measurement was 237 tonnes per day. Minor emissions from fumarolic vents in Main Crater continued to produce diffuse steam-rich plumes that rose as high as 2.4 km. PHIVOLCS reminded the public that the entire Taal Volcano Island is 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)