PHIVOLCS reported that unrest at Taal continued during 17-23 November. Sulfur dioxide emissions continued to be elevated, averaging 6,643-12,168 tonnes/day. Upwelling hot volcanic fluids were visible in the crater lake, and daily gas-and-steam plumes rose 1-3 km above the lake and drifted WNW, WSW, and SW. Low-level background tremor persisted along with 5-30 volcanic earthquakes per day, 2-4 low-frequency volcanic earthquakes per day, and 1-23 daily episodes of volcanic tremor, each lasting 1-5 minutes. One hybrid earthquake was recorded during 19-20 November and three were detected during 22-23 November. No earthquakes were recorded for a period during 18-19 November. Three short (1-5 minutes) phreatomagmatic bursts were recorded at 0811, 0817, and 0834 on 22 November. The events generated plumes that rose 200-1,500 m based on thermal camera images. PHIVOLCS stated that the events were likely driven by fracturing and gas release from magma beneath the Taal Volcano Island. The Volcano Alert Level remained at a 2 (on a scale of 0-5). PHIVOLCS reminded the public that the entire Taal Volcano Island is a Permanent Danger Zone (PDZ) and that boating on Taal Lake was 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)