MANILA - Phivolcs on Friday said it detected low-level activity in Taal Volcano.

According to Phivolcs, the Daang Kastila fissure in the volcano generated weak and shallow but continuous tremors since Friday early morning.

"The event was accompanied by increased thermal anomalies on the northern portion and upwelling of volcanic fluids in the Taal Main Crater Lake detected by remote cameras," it said in a statement.

"There has been a slight increase in SO2 degassing in the past two weeks indicated by a rise in the average emissions to 5,360 tonnes/day between 22 May and 1 June 2023 from averages of less than 3,000 tonnes/day between 1 April and 21 May 2023," Phivolcs added.

The agency also noted that the southwest Volcano Island inflated in May, indicating "shallow hydrothermal activity".

Phivolcs reminded the public that Alert Level 1, which notes abnormal condition, is still raised over Taal. According to the agency, the level warns of sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall and lethal accumulations or expulsions of volcanic gas.

"Should current low-level activity worsen or pronounced changes in monitored parameters forewarn of increasing unrest, the alert level may be raised to Alert Level 2," Phivolcs said.

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"DOST-PHIVOLCS strongly recommends that entry into TVI, Taal’s Permanent Danger Zone or PDZ, especially the vicinities of the Main Crater and the Daang Kastila fissure, must remain strictly prohibited. Local government units are advised to continuously assess previously evacuated barangays around Taal Lake for damages and road accessibilities and to strengthen preparedness, contingency and communication measures in case of renewed unrest.

"People are also advised to observe precautions due to ground displacement across fissures, possible ashfall and minor earthquakes. Civil aviation authorities must advise pilots to avoid flying close to the volcano as airborne ash and ballistic fragments from sudden explosions and wind-remobilized ash may pose hazards to aircrafts," it said.