TREMOR. The lower half of the record shows the low-level background tremor that has persisted in the Taal Volcano since March 29, 2022. This may signify stronger hydrothermal activity or degassing of the volcano. (Image courtesy of Phivolcs director Renato Solidum Jr.)

MANILA – Stronger hydrothermal activity in the Taal Volcano is likely as evidenced by the low-level background tremor that was detected, Philippine Institute of Volcanology and Seismology (Phivolcs) director Renato Solidum Jr. said Wednesday.

For the past 24 hours, Phivolcs recorded four volcanic tremors that lasted two to five minutes, and low-level background tremor has persisted since Tuesday.

"A low-level background tremor may signify stronger hydrothermal activity or boiling of groundwater, and degassing of the volcano," Solidum told the Philippine News Agency.

A low-level background tremor can be detected through a continuous vibration logged in the seismic instruments, Solidum added.

Based on Phivolcs' 24-hour period monitoring, activity at the Main Crater was dominated by the upwelling of hot volcanic fluids in its lake that generated plumes 1,500 meters high.

Sulfur dioxide emissions averaged 4,474 tons on Tuesday.

Alert Level 3 (magmatic unrest) is maintained over the Taal Volcano, indicating there is magmatic intrusion at the main crater that may further drive succeeding eruptions.

Magmatic intrusion refers to the rise of magma into shallower levels of the volcano, which can cause further explosions as the magma can explode because of gases inside it or when the magma interacts with groundwater in the shallower levels of the volcano.

Phivolcs has recommended the evacuation from Taal Volcano Island (TVI) and the high-risk barangays of Bilibinwang and Banyaga, Agoncillo and Boso-Boso, Gulod and eastern Bugaan East, Laurel, Batangas due to the possible hazards of pyroclastic density currents and volcanic tsunami should stronger eruptions subsequently occur.

Phivolcs also reiterated that entry into TVI and barangays of Agoncillo and Laurel must be prohibited, and all activities on Taal Lake should not be allowed.

Communities around the Taal Lake shores are likewise advised to remain vigilant, take precautionary measures against possible airborne ash and vog or volcanic smog. (PNA)