Taal Volcano's sulfur dioxide 'anomalously high' — Phivolcs

Published July 4, 2021, 4:40 PM

by Ellalyn De Vera-Ruiz

White smoke billowing out of Taal Volcano in Batangas on July 4, 2021 (ALI VICOY / MANILA BULLETIN)

Taal Volcano’s sulfur dioxide (SO2) has surged to a new high on Sunday, July 4, at 22,628 tonnes, exceeding the previous high of 14,699 tonnes on Saturday, July 3.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said the current SO2 parameters indicate an ongoing magmatic extrusion at the Taal Volcano’s main crater that may lead to explosions.

Since 12 a.m., July 4, Phivolcs also detected a total of 26 “strong and very shallow low-frequency” volcanic earthquakes associated with magmatic degassing beneath the eastern sector of the volcano island.

Some of these earthquakes were accompanied by rumbling and weakly felt by fish cage caretakers off the northeastern shorelines of the Taal Volcano Island.

“These observation parameters may indicate that an eruption similar to the July 1, 2021 event may occur anytime soon,” Phivolcs warned.

Last July 1, Taal Volcano generated a short-lived dark phreatomagmatic plume that reached one kilometer high, prompting Phivolcs to raise the volcano’s alert status from 2 to 3.

Phivolcs recommended the evacuation of residents in the Taal Volcano Island and high-risk barangays of Bilibinwang and Banyaga in Agoncillo town and Buso-buso, Gulod, and eastern Bugaan in Laurel town due to possible hazards of pyroclastic density currents and volcanic tsunami should stronger eruptions subsequently occur.

All activities on Taal Lake should not also be allowed at this time.

“Communities around the Taal Lakeshore are advised to remain vigilant, take precautionary measures against possible airborne ash and vog and calmly prepare for possible evacuation should unrest intensify,” Phivolcs said.

“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,” it added.