MANILA (UPDATED) - State seismologists on Friday night downgraded Taal Volcano's alert to Level 2 from Level 3, due to its "cessation of eruptive activities".
In an advisory, Phivolcs said the volcano's unrest was characterized by "declining volcanic gas emission, very slight ground deformation and positive microgravity anomalies."
"Alert Level 2 means that there is decreased unrest but should not be interpreted that unrest has ceased or that the threat of an eruption has disappeared," the agency said.
The state volcanologists also decided to lower the alert status after observing the following, among other things.
- "Migration" of shallow degassed magma, volcanic gas and/or hydrothermal fluids beneath the main crater and northeastern sector of Taal Volcano Island (TVI).
- Decrease in degassing activity or the "diminishing volumes of accumulated volcanic gas beneath TVI as well as the 'scrubbing' effects of rainfall-fed water recharge into Taal’s hydrothermal system."
- The presence of "moderate steam-laden plumes and periodic but generally less vigorous lake upwelling, consistent with decreased magmatic degassing" at the main crater.
The volcano, Phivolcs pointed out, could still have abrupt steam-driven phreatic explosions, volcanic earthquakes, ashfall, as well as "lethal accumulations or expulsions of volcanic gas" and might threaten the Taal Volcanic Island.
"Activity in the Main Crater has been more often characterized by the generation of moderate steam-laden plumes and periodic but generally less vigorous lake upwelling, consistent with decreased magmatic degassing," it added.
The agency added that there is a chance that the alert status could be hoisted to level 3 anew if an "uptrend" happens in the volcano related to "potential eruption."
It can further be downgraded to Level 1 if continued downtrend occur during the observation period.
Phivolcs also advised local officials to still prohibit entry to the island.
State seismologists hoisted Taal's alert status to Level 3 on July 1 following a phreatomagmatic eruption.
Taal's last eruption in January 2020 shot ash 15 kilometers high and spewed red-hot lava, crushing scores of homes, killing livestock and sending over 135,000 people into shelters.