The Philippine Institute of Volcanology and Seismology (Phivolcs) on Saturday, 5 October, recorded another phreatomagmatic eruption in Taal Volcano.

State volcanologists said the eruption at the Taal Main Crater lasted four minutes and produced a short black jetted plume followed by a steam-rich plume that rose 2,000 meters.

Traces of ash were reported in areas of Agoncillo, Batangas.

A total of five phreatic events were recorded on Saturday, according to Phivolcs.

Sulfur dioxide emissions since January this year remain high at 6,673 tonnes per day.

“The phreatomagmatic event was likely driven by sudden contact of water with a small branch of shallow magma that has been in place beneath the Taal Main Crater that has been degassing sustained levels of SO2 for the past three years,” Phivolcs explained.

Phivolcs, however, said that the background levels of volcanic earthquake activity and ground deformation detected at the Batangas-based volcano indicate that unrest is likely to progress into a major magmatic eruption “at this time.”

If phreatomagmatic activity at Taal persists or intensifies, Phivolcs said they may raise Alert Level 2 over the volcano.

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

Entry into the Taal Volcano Island remains strictly prohibited, particularly in the main crater and Daang Kastila fissures. 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.