Taal Volcano: Phivolcs detects another phreatic eruption, 4 quakes

DECEPTIVELY CALM The Taal Volcano Island, locally known as “Pulo,” is deceptively calm in this photo taken on Oct. 2, 2024, from a viewpoint in Tagaytay City amid its ongoing unrest, which has prompted state volcanologists to warn officials of towns and cities around Taal Lake to prepare for possible escalation of its alert level from 1 to 2. —SHERWIN TAN

LUCENA CITY — Taal Volcano in Batangas province recorded another minor phreatic eruption and four earthquakes on Friday, Nov. 29, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported.

“A minor phreatic eruption from Taal Volcano Island’s Main Crater at 11:25 AM today (29 November 2024), which generated a 1,200-meter white plume, was captured by the IP camera of the Agoncillo Observation Station,” Phivolcs said in a post on its Facebook page.

The eruption lasted six minutes, the agency noted in its bulletin Saturday morning, Nov. 30.

On Nov. 28 at 5:46 a.m., the volcano also had a minor steam-driven eruption that produced a 1,500-meter-high white plume.

A phreatic eruption occurs when water beneath the ground or on the surface is heated by magma, lava, hot rocks, or new volcanic deposits (for example, tephra and pyroclastic-flow deposits), Phivolcs explained.

READ: Taal Volcano logs 1,500-meter phreatic eruption

Over the past 24 hours, Phivolcs detected three volcanic earthquakes accompanied by three volcanic tremors that lasted two to six minutes.

Phivolcs defines volcanic earthquakes as those “generated by magmatic processes or magma-related processes beneath or near an active volcano.”

Volcanic tremors, on the other hand, are “continuous seismic signals with regular or irregular oscillations and low frequencies (typically 0.5–5 Hz) that can last for more than a minute.”

In its latest bulletin issued Saturday, Phivolcs recorded the emission of 6,307 metric tons of sulfur dioxide from Taal’s main crater, which rose 1,200 meters high before drifting southwest.

READ: Taal Volcano increases sulfur dioxide emission – Phivolcs

Phivolcs classified the volcano’s latest spewing activity as “voluminous emission.”

However, there was no reported upwelling of hot volcanic fluids in the Main Crater Lake on Taal Volcano Island.

No volcanic smog, or “vog,” was also observed during the latest monitoring period.

Taal Volcano is still under alert level 1 (low level of volcanic unrest), Phivolcs said.

The agency reminded the public that Taal Volcano remained in an “abnormal condition.”