Highest volcanic SO2 gas emission recorded from Taal Volcano

MANILA – The highest levels of volcanic sulfur dioxide (SO2) gas emission and tall, steam-rich plumes from the Taal Main Crater have been recorded Saturday.

In its 8 p.m. update, the Department of Science and Technology – Philippine Institute of Volcanology and Seismology (DOST-PHIVOLCS) said SO2 emission averaged 14,699 tonnes/day – the highest ever recorded in Taal, while upwelling in the Main Crater Lake generated steam plumes that rose 2,500 meters above Volcano Island.

Elevated SO2 emission, it added, maybe succeeded by eruptive activity at the main crater similar to increases in SO2 flux of 14,326 tonnes/day and 13,287 tonnes/day on June 28 and the morning of July 1, 2021, respectively, that preceded the short-lived phreatomagmatic eruption at 3:16 p.m. of July 1. 

Increased SO2, coupled with high relative humidities of 79-91% and wind velocities of 0 meters/second over Taal Lake based on All-Weather Stations data from the Taal Volcano Observatory and Volcano Island, is also likely to promote the formation of volcanic smog or vog over the lakeshore communities of Batangas Province.

DOST-PHIVOLCS is reminding the public that Alert Level 3 prevails over Taal Volcano and current SO2 parameters indicate ongoing magmatic extrusion at the Main Crater that may further drive succeeding explosions.

PHIVOLCS strongly recommends Taal Volcano Island and high-risk barangays of Bilibinwang and Banyaga, Agoncillo and Buso-buso, Gulod and eastern Bugaan, Laurel, Batangas Province remain evacuated due to the possible hazards of pyroclastic density currents and volcanic tsunami should stronger eruptions subsequently occur.

The public is also reminded that the entire Taal Volcano Island is a Permanent Danger Zone (PDZ), and entry into the island as well as high-risk barangays of Agoncillo and Laurel must be prohibited.

All activities on Taal Lake should not be allowed at this time. Communities around the Taal Lake shores are advised to remain vigilant, take precautionary measures against possible airborne ash and vog and calmly prepare for possible evacuation should unrest intensify.

Because of unprecedented high SO2 degassing from Taal Main Crater, local government units are additionally advised to conduct health checks on communities affected by vog to assess the severity of SO2 impacts on their constituents and to consider temporary evacuation of severely exposed residents to safer areas. Civil aviation authorities must advise pilots to avoid flying over Taal Volcano Island as airborne ash and ballistic fragments from sudden explosions and pyroclastic density currents such as base surges may pose hazards to aircraft.

DOST-PHIVOLCS maintains its close monitoring of Taal Volcano and any new development will be communicated to all concerned stakeholders. (PR)