The Philippine Institute of Volcanology and Seismology (Phivolcs) has monitored more earthquakes in Taal Volcano and Mt. Pinatubo in the last 24 hours.
In separate bulletins issued on Monday, May 17, Phivolcs said Taal Volcano has 82 earthquakes, including 15 low-frequency earthquakes and 67 tremor events having durations of one to six minutes, and low-level background tremor that has persisted since April 8.
Meanwhile, Pinatubo Volcano’s monitoring network recorded 42 earthquakes during its 24-hour observation period.
Taal’s sulfur dioxide emission increases
Its main crater showed a “weak” emission of steam-laden plumes from fumaroles or gas vents that rose 40 meters, Phivolcs said.
Taal Volcano’s sulfur dioxide emission also increased to 3,758 tonnes per day as recorded on Sunday, May 16, from an average of 2,546 tonnes per day on Saturday, May 15.
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, 2021, respectively.
Phivolcs added that ground deformation parameters continued to indicate a “very slow and steady inflation and expansion of the Taal region that began after the January 2020 eruption.”
“These parameters indicate persistent magmatic activity at shallow depths beneath the edifice,” it said.
“Alert Level 2 (increased unrest) is currently maintained over Taal Volcano,” Phivolcs pointed out.
The restive volcano in Batangas has been under Alert Level 2 since March 9, 2021.
“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 TVI (Taal Volcano Island),” Phivolcs pointed out.
It warned the public from entering the volcano island, which is a permanent danger zone, especially the vicinities 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.
Mt. Pinatubo still under Alert Level 1
Phivolcs said Mt. Pinatubo remains under “abnormal” condition, which means that there is low-level unrest that may be related to tectonic processes beneath its edifice.
Its status was raised to Alert Level 1 on March 4, 2021.
However, Phivolcs pointed out that no imminent eruption is foreseen.
“Entry into the Pinatubo Crater area must be conducted with extreme caution and should be avoided if possible,” Phivolcs advised.
Communities and local government units surrounding Pinatubo were also reminded to be always prepared for both earthquake and volcanic hazards and to review, prepare and strengthen their contingency, emergency, and other disaster preparedness plans.