A total of 171 quakes and 1.5-kilometer-high plumes have been observed at Taal Volcano in the last 24 hours, said the Philippine Institute of Volcanology and Seismology (Phivolcs) on Tuesday, July 13.
Of the total quakes, Phivolcs said Taal had 13 low-frequency volcanic earthquakes, 157 tremor events having durations of one to 97 minutes, including a low-level background tremor that has persisted since July 7.
Moreover, high levels of volcanic sulfur dioxide (SO2) emissions generated 1.5-kilometer-tall steam-rich plumes above Taal Volcano’s main crater.
As of July 12, Monday, the average SO2 emission of Taal Volcano was measured at 6,134 tonnes.
Its record-high SO2 emission was 22,628 tonnes on July 4.
Phivolcs said that Taal Volcano remains at Alert Level 3 due to continuous "magmatic unrest." It has been under this status since July 1.
"At Alert Level 3, magma extruding from the main crater could drive explosive eruption," Phivolcs said.
The public is prohibited from entering the entire Taal Volcano Island, which is a permanent danger zone.
Phivolcs also advised those in the high-risk barangays of Agoncillo and Laurel in Batangas to remain in evacuation centers due to hazards of pyroclastic density currents and volcanic tsunami in case of strong eruptions.
"All activities on Taal Lake should not be allowed at this time," it added.
Communities around the Taal lakeshores were also advised to remain vigilant and take precautionary measures against possible airborne ash and vog.
Phivolcs asked residents around Taal Lake to "calmly" prepare for possible evacuation should Taal Volcano's unrest intensifies.