Philippine Institute of Volcanology and Seismology (PHIVOLCS) issued advisories for Taal reporting that a total of 18 phreatic events were recorded almost daily during 22 September-2 October. There were 1-3 daily phreatic events during 22-23 and 25-30 September, each lasting 1-8 minutes long based on visual, seismic, and infrasound data. Five of the events occurred during 0110-0437 on 1 October. Daily white steam-and-gas emissions that were sometime voluminous rose 0.7-2.1 km above the crater rim and drifted in multiple directions. Hot fluids were visible upwelling in the lake almost daily. A phreatomagmatic eruption recorded during 1621-1632 on 2 October ejected short black jets of material followed by a voluminous steam-rich plume that rose 2.4 km and drifted NE. PHIVOLCS concluded that the event was likely driven by water contacting a small body of shallow magma that has been steadily degassing for the previous three years; deformation and seismic data were at background levels and did not indicated that the unrest would escalate into a large magmatic eruption. Sulfur dioxide emissions were measured a few times during 22 September-2 October and trended downward, averaging 8,927 tonnes per day (t/d) on 21 September, 4,899 t/d on 23 September, 1,510 t/d on 28 September, 1,354 t/d on 30 September, and 2,532 t/d on 2 October. PHIVOLCS noted that sulfur dioxide emissions had been high in 2024, averaging 6,712 t/d since January. 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) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain 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)