File photo of Taal Volcano. —INQUIRER file photo / GRIG C. MONTEGRANDE
LUCENA CITY — Taal Volcano on Thursday, November 9, spewed another record-high volume of sulfur dioxide for the year, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
“A total of 11,499 tonnes/day of volcanic sulfur dioxide or SO2 gas emission from the Taal Main Crater was measured today, 09 November 2023. This is the highest recorded SO2 emission from Taal for the year,” Phivolcs said in an advisory issued at 3 p.m.
On October 12, Taal Volcano recorded 9,762 tonnes/day of volcanic sulfur dioxide from the main crater of the volcano that sits on Taal Volcano island (TVL) in the middle of Taal Lake in Batangas province.
The state volcanologists said that their visual monitors show “continued pronounced upwelling of volcanic fluids in the Main Crater that generated rather short and weak- to moderate-volume degassing plumes.”
The agency said that strong winds drifted the plumes to the southwest but no volcanic smog or vog over Taal Caldera was observed throughout the day.
However, the wind forecasts of the Philippine Atmospheric, Geophysical and Astronomical Services Administration indicate a probable weakening of wind later in the day and tomorrow, November 10, “which may lead to potential SO2 accumulation and vog formation” over the Taal region, the Phivolcs said.
READ: Taal Volcano update: 3 quakes in 24 hours; Alert Level 1 stays
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 with severities depending on the gas concentrations and durations of exposure.
Authorities warned that people who may be particularly sensitive to vog are those with health conditions such as asthma, lung disease and heart disease, the elderly, pregnant women and children.
Local governments were asked to continuously monitor and assess volcanic O2 and vog exposure of, and potential impacts on, their communities and undertake appropriate response measures to mitigate these hazards.
“In addition, acid rain can be generated during periods of rainfall and volcanic gas emission over areas where the plume disperses, causing damage to crops and affecting metal surfaces such as roofs of houses and buildings,” the Phivolcs warned.
The Phivolcs reported that Taal Volcano has been continuously degassing high concentrations of volcanic SO2 since March 2021 and emissions since September 2023 have averaged 5,019 tonnes/day.
Moderate tremors have been recently exhibited by the volcano, according to Phivolcs.
“Of the 415 volcanic earthquakes recorded since 1 September 2023, 362 were weak volcanic tremors associated with volcanic gas activity,” it reported.
Taal Volcano remains under alert level 1 (low level of volcanic unrest), according to the state volcanologist.
Phivolcs reminded the public that Taal Volcano remained in an “abnormal condition” and “should not be interpreted to have ceased unrest nor ceased the threat of eruptive activity.”
Under alert level 1, sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within Taal Volcano Island, Phivolcs said.
Phivolcs said entry into the volcano island and Taal’s permanent danger zone, especially the vicinity of the main crater and the Daang Kastila fissure, as well as human activities on Taal Lake, must be prohibited.