The Philippine Institute of Volcanology and Seismology (Phivolcs) has not detected earthquakes in Taal Volcano in the past 24 hours but a low-level background tremor has persisted since April 8.

Science and Technology Undersecretary and Phivolcs OIC Renato Solidum explained in March that a low-level background tremor is a continuous low-energy volcanic tremor.

He pointed out that tremors may last more than a minute, even several days, and are associated with specific volcanic processes. Meanwhile, a volcanic earthquake lasts less than a minute.

In the volcano bulletin issued on Friday, May 28, Phivolcs said the activity at the main crater was dominated by the upwelling of hot volcanic fluids in its lake which generated plumes that reached one-kilometer high.

Sulfur dioxide (SO2) emission increased to 5,627 tonnes per day on Thursday, May 27, from 1,263 tonnes per day on Wednesday, May 26.

Meanwhile, temperature highs of 71.8°C and pH of 1.59 were last measured from the main crater lake on March 4, 2021 and Feb. 12, 2021, respectively.

"Ground deformation parameters from electronic tilt, continuous GPS and InSAR monitoring continue to record a very slow and steady inflation and expansion of the Taal region that began after the January 2020 eruption," Phivolcs said.

It pointed out that these parameters continue to indicate a persistent magmatic activity at shallow depths beneath the Taal Volcano.

As it continues to show signs of elevated unrest, Taal Volcano's status remains under Alert Level 2.

The restive volcano in Batangas has been under Alert Level 2 since March 9, 2021.

Phivolcs reiterated that entry into the volcano island, which is a permanent danger zone, especially the vicinities of the main crater and Daang Kastila fissure, is strictly prohibited.