The Philippine Institute of Volcanology and Seismology (Phivolcs) has recorded 254 volcanic earthquakes including 220 episodes of volcanic tremor lasting one to 27 minutes in the 24-hour monitoring of Taal Volcano.

In its volcano bulletin issued on Thursday, April 1, it also noted 33 low frequency volcanic earthquakes, and one volcano-tectonic earthquake.

"Activity at the Main Crater consisted of weak emission of steam-laden plumes rose five meters high," Phivolcs said.

"Sulfur dioxide (SO2) emission averaged 509 tonnes/day yesterday, March 31, 2021. Temperature highs of 71.8°C and pH of 1.59 were last measured from the Main Crater Lake respectively on March 4 and February 12, 2021," it added.

Phivolcs said ground deformation parameters also indicated a “very slow and steady inflation and expansion of the Taal region after the January 2020 eruption.”

"These parameters may indicate increased magmatic activity at shallow depths beneath the edifice," it said.

Phivolcs said Alert Level 2 (increased unrest) is currently maintained over Taal Volcano but that "unrest has been elevating and is under constant evaluation."

"DOST-PHIVOLCS reminds the public that at Alert Level 2, sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within and around Taal Volcano Island," it said.

"DOST-PHIVOLCS strongly recommends that entry must be strictly prohibited into Taal Volcano Island, Taal’s Permanent Danger Zone or PDZ, especially the vicinities of the Main Crater and the Daang Kastila fissure, and occupancy and boating on Taal Lake," added Phivolcs.