PHIVOLCS reported that a series of seven significant but shallow tremors were recorded at Taal by all 15 seismic stations of the Taal Volcano Network during 0609-0900 on 13 July. Most of the events were located SE of Taal Volcano Island (TVI). Infrared camera images of Main Crater lake indicated increased thermal output. The report noted that sulfur dioxide emissions had been elevated during the previous two weeks, averaging 5,866 tonnes/day (t/d) and peaking at 9,623 t/d on 6 July. Upwelling gasses and fluids in the lake were periodically visible. Electronic tilt data indicated inflation at the N flank of TVI since May 2023.

During 11-18 July there were 2-16 daily volcanic earthquakes including 1-13 periods of volcanic tremor (each lasting 1-5 minutes long); a period of tremor that began at 1210 on 16 July was ongoing through 17 July. Upwelling gasses and fluids in the lake were visible on a few of the days; vog was reported around the caldera during 11-12 July. Daily emissions of gas-and-steam rose 0.9-2.4 km and drifted SW, SE, NE, and NW. 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)