The Philippine Institute of Volcanology and Seismology (Phivolcs) on Monday, July 11, lowered Taal Volcano’s alert status from Level 2 to Level 1.
It said that the downgrading of the Taal Volcano’s alert status “reflects the overall decrease in the level of monitoring parameters.”
In the past two months of monitoring the Taal Volcano, Phivolcs has observed “baseline volcanic earthquake activity, stabilizing ground deformation of the Taal Caldera and Taal Volcano Island (TVI) edifices, and weak degassing and surface activity at the main crater.”
Phivolcs recorded a decline in the daily average of volcanic earthquakes from seven events per day between January 1 and May 31, 2022. However, it has not detected any earthquakes since June 13.
“The sustained seismic quiescence for the past month indicates that degassing and rock-fracturing processes related to magmatic activity beneath TVI have abated, and that the possibilities of magma intrusion into the main crater have significantly decreased,” it explained.
Moreover, Phivolcs observed lower sulfur dioxide (SO2) emissions “consistent with the weakened degassing from magma beneath the Taal Volcano Islands and volcanic gas being efficiently absorbed by the main crater lake and by Taal’s recovered hydrothermal system.”
“Surface activity has declined to weak emission of 300-meter to 2,400-meter tall steam-rich plumes from fumaroles or active gas vents on the Main Crater. The last significant activities from the main crater were phreatomagmatic bursts on 2 and 10 February and 26 March 2022 that respectively spewed 300-meter and 3,000-meter tall steam-rich plumes. Since then, background hydrothermal activity in the main crater lake has been quietly transpiring,” it added.
However, Phivolcs pointed out that Alert Level 1 status means that the volcano is “still in abnormal condition and should not be interpreted that unrest has ceased or that the threat of an eruption has disappeared.”
“Should an uptrend or pronounced change in monitored parameters forewarn of renewed unrest, the Alert Level may be raised back to Alert Level 2,” it said.
“Residents of areas at high risk to base surges who have returned after the step-down to Alert Level 2 on 23 July 2021 must therefore remain vigilant and always prepared for a quick and organized evacuation. Conversely, should there be a return of monitoring parameters to baseline levels after a sufficient observation period, the Alert Level will be further lowered to Alert Level 0,” it added.
Phivolcs also reminded the public that the entire Taal Volcano Island is a permanent danger zone, and that entry into the island and high-risk areas must be strictly prohibited.