A weak phreatic or steam-driven eruption occurred at the Taal Volcano’s main crater between 8:27 a.m. and 8:31 a.m. on Wednesday, May 8, the Philippine Institute of Volcanology and Seismology (Phivolcs) said in an advisory.

Phivolcs said the eruption produced white and steam-filled plumes that rose 2,000 meters above the main crater and then drifted southwest.

This volcanic activity was attributed to the continued emission of hot volcanic gases from the main crater.

“Sulfur dioxide (SO2) emissions have decreased last week and averaged 2,191 tons per day on May 6, 2024. Nonetheless, average SO2 emissions since January this year remain high at 8,913 tons per day,” it said.

While similar phreatic events could follow, Phivolcs said the volcanic unrest is unlikely to progress to a magmatic eruption.

Alert Level 1 stays

Phivolcs explained that Taal Volcano remains on Alert Level 1, indicating that it is still in an abnormal state and should not be interpreted as having ceased unrest or the threat of eruptive activity.

Phivolcs added that sudden steam-driven or phreatic explosions, volcanic earthquakes, small amounts of ashfall, and potentially fatal buildups or releases of volcanic gas are all potential threats to Taal Volcano Island (TVI) at Alert Level 1.

It also warned the public that the degassing of high concentrations of volcanic SO2 may pose long-term health risks to communities around Taal Caldera, which are frequently exposed to volcanic gas.

Permanent danger zone

Phivolcs reminded that entering TVI, Taal’s permanent danger zone, particularly near the main crater and the Daang Kastila fissure, is strictly prohibited.

“Local governments should continuously monitor and assess their communities’ preparedness, as well as implement appropriate response measures, to mitigate hazards posed by long-term degassing and related phreatic activity,” it said.

“Civil aviation authorities must advise pilots to avoid flying close to the volcano because airborne ash and ballistic fragments from sudden explosions, as well as wind-remobilized ash, can pose a threat to aircraft,” it added.

The last phreatic eruption at Taal Volcano occurred on April 28.