Phivolcs warns Taal residents vs. volcanic smog, acid rain

FILE: Taal Volcano as seen from Tagaytay. (Photo by Yla Corotan – Own work, CC BY-SA 3.0)

MANILA – The Philippine Institute of Volcanology and Seismology (Phivolcs) on Wednesday warned of significant volcanic smog or “vog” active forming over Taal Caldera and its surrounding areas as degassing of the Taal Main Crater continues.

In an advisory issued at 11 a.m., Phivolcs said it has observed visible upwelling of volcanic fluids in the Main Crater Lake and generation of voluminous steam-rich plumes reaching 2,000 meters above the Taal Volcano Island.

Vog consists of fine droplets containing volcanic gas which is acidic and can cause irritation of the eyes, throat and respiratory tract in severities depending on the gas concentrations and durations of exposure.

The Phivolcs said the vog could persist over the Taal region while degassing, weak wind movement and humid atmosphere prevail.

It also said that an average of 7,680 tonnes of volcanic sulfur dioxide emission was recorded on June 6, which was preceded by an average of 9,391 tonnes on June 5.

Phivolcs urges the communities near the volcano to limit their exposure to vog by avoiding outdoor activities and closing the doors and windows.

They are also urged to use an N95 mask and drink plenty of water to reduce throat irritation.

“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,” Phivolcs said, adding that they should seek help from a doctor or barangay health unit, especially if they experience serious effects.

Meanwhile, Phivolcs said 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 roofs of houses and buildings.

Taal Volcano has been under Alert Level 1 (abnormal) since July 11, 2022. Sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ash fall and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within TVI.

Entry into TVI, especially the vicinities of the Main Crater and the Daang Kastila fissure, remains strictly prohibited, Phivolcs said.

Local government units are also advised to continuously assess previously evacuated barangays around Taal Lake for damages and road accessibilities, and to strengthen preparedness, contingency and communication measures in case of renewed unrest.

People are advised to observe precautions due to ground displacement across fissures, possible ash fall and minor earthquakes.

An increase in Taal’s degassing activity was also observed over the weekend.

On Monday, the Civil Aviation Authority of the Philippines has advised pilots to avoid flying near the Taal Volcano’s summit as sudden eruption may pose threat to aircraft up to 10,000 ft, it said.