State volcanologists recorded a slight increase in tremors as well as changes at the Main Crater Lake of Taal Volcano in the province of Batangas.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said in an advisory at 3:30 pm on Monday, February 15, that it observed “slightly increased seismic activity” at the volcano.

There were “50 relatively weak tremor episodes” from 5 am to 3 pm on Monday alone.

“These tremor episodes ranged in duration from 2 to 5 minutes and occurred at shallow depths of less than 1 kilometer, signaling increased hydrothermal activity beneath Taal Volcano Island,” Phivolcs said.

Since Saturday, February 13, there have been “68 shallow tremor episodes” in Taal Volcano Island, added the agency.

Aside from the volcanic tremors, Phivolcs noted an “increase in acidity and temperature” of the Main Crater Lake.

Data showed “continuous acidification of lakewater from a pH 2.79 to pH 1.59 between January 2020 and February 2021” and “an unseasonal temperature high of 77ºC.”

Phivolcs reminded the public that Taal Volcano remains under Alert Level 1, which means it is in an “abnormal” state.

Phivolcs warned that “there are increased possibilities of sudden steam-driven or phreatic explosions, hazardous volcanic gas, and minor ashfall from the Main Crater Lake.”

The agency also reiterated that entry into Taal Volcano Island, “especially the vicinities of the Main Crater Lake and the Daang Kastila fissure, must remain strictly prohibited.”

Taal Volcano has been under Alert Level 1 since March 19, 2020, from a high of Alert Level 4 when it last erupted on January 12, 2020.

The January 2020 eruption affected over half a million people in the provinces of Batangas, Quezon, Laguna, and Cavite, prompting President Rodrigo Duterte to declare a state of calamity in the region of Calabarzon in late February 2020. – Rappler.com