Taal and Pinatubo volcanoes continued to show low level of unrest during the 24-hour observation of the active volcanoes from 8 a.m., March 4 (Thursday) to 8 a.m., March 5 (Friday).
In its volcano bulletin issued on Friday, the Philippine Institute of Volcanology and Seismology (Phivolcs) monitored 18 earthquakes in Taal Volcano and nine quakes in Mt. Pinatubo in the past 24 hours.
Likewise, Phivolcs' volcano network in Taal recorded two volcanic tremor episodes with durations ranging from two minutes to three minutes.
The activity at the Taal Volcano's main crater consisted of weak emission of steam-laden plumes from fumarolic vents that rose 10 meters high, it added.
Temperature highs of 71.8 degrees Celsius 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 continuous electronic tilt on volcano island record a slight deflation around the main crater since October 2020 but overall, very slow and steady inflation of the Taal region has been recorded by continuous GPS (global positioning system) data after the eruption (in January 2020)," Phivolcs said.
Both Taal Volcano and Mt. Pinatubo remain under alert level 1, which means the volcanoes are still under "abnormal" state.
Mt. Pinatubo is under a "low-level unrest" that may be related to tectonic processes beneath the volcano but Phivolcs foresees no imminent eruption.
"Entry into the Pinatubo crater area must be conducted with extreme caution and should be avoided if possible. Communities and local government units surrounding Pinatubo are 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," Phivolcs said.
Meanwhile, threats of sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas remain in Taal Volcano.
Phivolcs said entry into the Taal volcano island, which is a permanent danger zone, especially the vicinities of the main crater and Daang Kastila fissure, should be strictly prohibited.
"Local government units are advised to continuously assess and strengthen the preparedness of previously evacuated barangays around Taal Lake in case of renewed unrest. Civil aviation authorities must advise pilots to avoid flying close to the volcano as airborne ash and ballistic fragments from sudden explosions and wind-remobilized ash may pose hazards to aircraft," it said.