The Philippine Institute of Volcanology and Seismology (Phivolcs) has detected four earthquakes that include one tectonic event and three low-frequency quakes and low-level background tremor in Taal Volcano in Batanga in the past 24 hours.
The Taal Volcano has been Alert Level 2 since March 9, 2021.
In its latest volcano bulletin issued on Thursday, Phivolcs observed a "weak" emission of steam-laden plumes from Taal Volcano's vents that rose 10 meters.
The volcano's sulfur dioxide emission averaged 1,602 tonnes per day on Wednesday, April 7.
Meanwhile, temperature highs of 71.8 degrees Celsius and pH of 1.59 were last measured from the main crater lake on March 4 and Feb. 12, respectively.
Phivolcs added that ground deformation parameters continued to indicate a “very slow and steady inflation and expansion of the Taal region after the January 2020 eruption."
Phivolcs said 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 (TVI).
It warned the public against entering the volcano island, which is a permanent danger zone, especially the vicinity of the main crater and Daang Kastila fissure.
Occupancy and boating on Taal Lake should also be strictly prohibited, Phivolcs added.
Local government units were advised to continuously assess and strengthen the preparedness of previously evacuated barangays around Taal Lake in case of renewed unrest.
Civil aviation authorities were also asked to advise pilots to avoid flying close to the volcano as airborne ash and ballistic fragments from explosions and wind-remobilized ash may pose hazards to aircraft.