Phreatic eruption observed at Taal Volcano — PHIVOLCS

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) on Saturday reported a steam-driven or phreatic eruption at Taal Volcano in Batangas.

Based on its 24-hour monitoring bulletin as of midnight Saturday, PHIVOLCS observed a phreatic eruption with a duration of two minutes and five volcanic tremors lasting three to 608 minutes.

The development comes two days after state volcanologists monitored an increase in degassing activity at Taal.

Taal's main crater emitted 11,072 tons of volcanic sulfur dioxide. Vog or volcanic smog was also observed. The emission, however, was lower than 18,638 tons recorded on March 28.

State volcanologists had previously said Taal Volcano has continuously degassing “voluminous concentrations” of sulfur dioxide since 2021 and has emitted an average of 8,294 tonnes a day this year.

Taal Volcano remains at Alert Level 1, characterized by "low-level unrest."

A 2,400-meter tall plume described as a "voluminous emission" was also reported Saturday, which drifted south-southeast to north-northwest.

Long-term deflation of the Taal caldera was observed, accompanied by short-term inflation of the general northern and southeastern flanks of the Taal Volcano Island.

PHIVOLCS warned that sudden explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas posed serious health and safety risks.

Entry into the Taal Volcano Island, particularly in the main crater and Daang Kastila fissures, remains strictly prohibited. The island has been identified as a permanent danger zone.

Aircraft that fly close to the volcano, PHIVOLCS said, will be at risk of coming into contact with airborne ash and ballistic fragments.

Near zero visibility

Meanwhile, GMA Regional TV reported late Friday that the area around Taal Volcano Island experienced near zero visibility due to haze and vog.

PHIVOLCS said it was caused by the continuous release of sulfur dioxide from Taal, which was getting trapped in the atmosphere. The wind in the area was also slow, contributing to the haze to linger.

Despite the haze, business continued as usual by the lakeside in Barangay Halang, Lipa City, with no unusual odors reported.

"Wala naman po, yun lang [na] hindi nakikita 'yung [bulkan], hindi kagaya kahapon (We're fine, although we are unable to see the volcano, unlike yesterday)," Lea Macasaet, a resident, said.

In a separate interview, Bacolcol said, "Although 'yun na nga, kung wala silang masangsang na amoy na naamoy, then na-mix na sa aerosol 'yung sulfur dioxide (Although they don't smell anything foul, that means the sulfur dioxide has become an aerosol after mixing with the air)."

Haze

On June 6, a haze was observed in various towns in Batangas including: Alitagtag, Tingloy, San Nicolas, Laurel, Taysan, Lobo, Agoncillo, Lemery, Taal, Sta. Teresita, Cuenca, Balete, Malvar, and the cities of Lipa and Batangas.

The public was advised to wear N95 face masks, avoid outdoor activities, and keep windows closed. Those with pre-existing health conditions, children, and the elderly, in particular, should take caution.

Vog is a toxic gas mixture of sulfur dioxide and other volcanic gases that combine with atmospheric oxygen, moisture, dust, and sunlight, resulting in a hazy environment.

Prolonged exposure to vog may irritate the eyes, throat, and respiratory tract. — VDV, GMA Integrated News