(Eagle News) — Taal Volcano is now under Alert Level 3, after the Philippine Institute of Volcanology and Seismology (PHIVOLCS) reduced its alert level because of decreasing volcanic activity.
There is now decreased tendency for hazardous eruption.
PHIVOLCS said that it had observed a reduced number of earthquakes in the area, as well as ground deformation.
Ash eruptions also weakened and sulfur dioxide emissions have a decreasing trend, PHIVOLCS senior science research specialist Paul Alanis told Eagle News Service.
“This serves as a notice for the lowering of Taal Volcano’s status from Alert Level 4 (hazardous eruption imminent) to Alert Level 3 (decreased tendency towards hazardous eruption),” PHIVOLCS said in the latest bulletin issued at 8 a.m. on Sunday, Jan. 26.
It said that “Taal Volcano’s condition in the two weeks following the 12-13 January 2020 phreatomagmatic eruption (main eruptive phase) has generally declined into less frequent volcanic earthquake activity, decelerated ground deformation of the Taal Caldera and Taal Volcano Island (TVI) edifices and weak steam/gas emissions at the Main Crater.”
PHIVOLCS said that these observations were supported by several parameters including reduced number of significant earthquakes, reduced inflation activity or ground deformation in Taal Volcano and its surroundings, diminishing ash eruptions, and sulfur dioxide emissions.
This generally means that magmatic activity in Taal Volcano has slightly reduced.
“In view of the above observations, PHIVOLCS-DOST is lowering the alert status of Taal Volcano from Alert Level 4 to Alert Level 3 to reflect the overall decrease in the level of monitoring parameters,” the latest bulletin said.
“Alert Level 3 means that there is a decreased tendency towards hazardous explosive eruption but should not be interpreted that unrest has ceased or that the threat of a hazardous eruption has disappeared,” it explained.
PHIVOLCS said that should there be an “uptrend or pronounced change in monitored parameters forewarn a potential hazardous explosive eruption, the Alert Level may be raised back to Alert Level 4.”
Because of this, “people residing within areas at high risk to base surges who have returned after the Alert Level was stepped down must thus be prepared for a quick and organized evacuation at such time.”
“Conversely, should there be a persistent downtrend in monitored parameters after a sufficient observation period, the Alert Level will be further lowered to Alert Level 2,” it added.
PHIVOLCS also reminded the public that even under Alert Level 3, there could be “sudden steam-driven and even weak phreatomagmatic explosions, volcanic earthquakes, ashfall and lethal volcanic gas expulsions” that can threaten areas within Taal Volcano Island and nearby lakeshores.
Because of the lowering of the alert level, only those inside “Taal’s Permanent Danger Zone, as well as into areas over Taal Lake and communities west of TVI within a seven (7) kilometer-radius from the Main Crater” are considered stricyly prohibited areas.
When Taal Volcano was still under Alert level 4, the prohibited areas are those within 14 kilometers from the Taal’s main crater.
“Local government units are advised to assess areas outside the seven-kilometer radius for damages and road accessibilities and to strengthen preparedness, contingency and communication measures in case of renewed unrest,” PHIVOLCS said.
“People are also advised to observe precautions due to ground displacement across fissures, frequent ashfall and minor earthquakes. Communities beside active river channels particularly where ash from the main eruption phase has been thickly deposited should increase vigilance when there is heavy and prolonged rainfall since the ash can be washed away and form lahars along the channels,” it added.