'Short-lived' phreatomagmatic burst occurred in Taal Volcano — Phivolcs

Published November 16, 2021, 9:46 AM

by Ellalyn De Vera-Ruiz


Taal Volcano had a “short-lived” phreatomagmatic burst, which generated a 2.4-kilometer plume on Monday evening, Nov. 15, said the Philippine Institute of Volcanology and Seismology (Phivolcs).

“A short-lived phreatomagmatic burst was recorded at 11:39 p.m. yesterday (Nov. 15) as a volcanic tremor event that lasted three minutes based on its seismic signal,” Phivolcs said in its volcano bulletin.

It said that the event produced a single plume about 2,400 meters high before it drifted southwest.

A phreatomagmatic eruption occurs when magma comes into contact with groundwater.

In the past 24 hours, Phivolcs detected volcanic earthquakes, including seven volcanic tremor events having durations of one to three minutes, and three low-frequency volcanic earthquakes, as well as a low-level background tremor that has persisted since July 7.

Taal Volcano also continued to emit high levels of sulfur dioxide (SO2), which averaged 12,516 tons per day on Monday. Its highest ever recorded emission was on Oct. 5 with an average of 25,456 tons.

“Based on ground deformation parameters from electronic tilt, continuous GPS and InSAR monitoring, Taal Volcano Island (TVI) has been inflating since August 2021 while the Taal region continues to undergo very slow extension since 2020,” Phivolcs pointed out.

Phivolcs reminded the public that Taal Volcano remains under alert level 2, which means that the volcano continues to manifest “increased unrest.”

“At Alert Level 2, sudden steam- or gas-driven explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within and around TVI,” it said.

The volcano has been under alert level 2 since July 23, 2021.

Phivolcs reiterated that entry into the Taal Volcano Island, which is a permanent danger zone, especially the vicinities of the main crater and the Daang Kastila fissure, is strictly prohibited.

Boating on Taal Lake is also prohibited, it said.