MANILA, Philippines – Batangas province’s Taal Volcano emitted 9,762 tons per day of sulfur dioxide (SO2) on Thursday, October 12, its highest recorded emission so far for 2023.

The Philippine Institute of Volcanology and Seismology (Phivolcs) alerted the public about the “increased and continuous degassing” in an advisory at 6 pm on Thursday.

“Visual monitors show continued pronounced upwelling of volcanic fluids in the main crater that generated rather short and weak to moderate volume degassing plumes,” Phivolcs said.

SO2 is a major gas component of magma.

Phivolcs noted that Taal Volcano’s SO2 emission levels have been high since March 2021.

Since September 2023, emissions have averaged 3,781 tons per day.

The high levels of SO2 have led to volcanic smog or vog in parts of Batangas and nearby areas in recent months, causing illnesses and disrupting classes.

There was no vog observed over the Taal area on Thursday, but Phivolcs warned that vog could again be generated if the elevated degassing continues and wind speeds “significantly decrease” in the coming weekend as predicted by the weather bureau.

“As a reminder, vog consists of fine droplets containing volcanic gas such as SO2 which is acidic and can cause irritation of the eyes, throat, and respiratory tract,” Phivolcs said.

People with respiratory and heart illnesses, the elderly, pregnant women, and children are most vulnerable to vog.

Phivolcs advised those affected by vog to stay indoors, shut doors and windows, use N95 face masks, and seek medical help if needed.

Acid rain is also possible “during periods of rainfall and volcanic gas emission.” This could damage crops and metal roofs of houses and buildings.

Taal has been under Alert Level 1 or “in abnormal condition” since July 11, 2022. “Sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas” are possible.

Entry into Taal Volcano Island, a permanent danger zone, remains prohibited. – Rappler.com