A total of 92 earthquakes, consisting of 10 low-frequency quakes and 82 tremors, was detected in Taal Volcano in the last 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Saturday, June 19.
Phivolcs said the volcanic tremors lasted two minutes to four hours, while a low-level background tremor has persisted since April 8, 2021.
Moreover, the activity at Taal's main crater was still dominated by the upwelling of hot volcanic fluids in its lake which generated plumes 500 meters high.
Phivolcs also noted that Taal Volcano continues to register high sulfur dioxide emission, averaging 3,007 tonnes daily on Friday, June 18.
"Based on ground deformation parameters from electronic tilt, continuous GPS and InSAR monitoring, Taal Volcano Island has begun deflating in April 2021 while the Taal region continues to undergo very slow extension since 2020," it said.
Phivolcs pointed out that these parameters indicate overall that magmatic unrest continues to occur at shallow depths beneath the edifice, thus Alert Level 2 is maintained.
Taal Volcano has been under Alert Level 2 since March 9, 2021.
Phivolcs reiterated that there remains a possibility of sudden steam- or gas-driven explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas that can occur and threaten areas within and around the Taal Volcano Island.
It said that entry into the volcano island, which is a permanent danger zone, especially the vicinities of the main crater and Daang Kastila fissure, should be strictly prohibited.