The Philippine Institute of Volcanology and Seismology (Phivolcs) has raised Mayon Volcano’s alert status from Alert Level 1 (low-level unrest) to Alert Level 2 (increasing or moderate unrest) as of Thursday.

In a bulletin, Phivolcs said the current unrest at Mayon is being driven by shallow magmatic processes, which may lead to a hazardous magmatic eruption.

On Wednesday, a total of 47 rockfall events were recorded, the highest number documented in a single day over the past year. The agency noted that increased rockfall activity has previously preceded magmatic dome growth in the volcano’s upper slopes, similar to conditions observed prior to the 2023 eruption.

While no significant increase in volcanic earthquakes or sulfur dioxide emissions has been observed, Phivolcs said ground deformation has remained unusual for nearly 18 months, unlike in 2023.

Long-term monitoring using electronic distance measurement (EDM), continuous GPS, and electronic tilt data shows that the Mayon edifice—particularly its eastern and northeastern slopes—has been inflating since June 2024. Short-term swelling on the western and southwestern slopes has also been detected since May 2025.

Phivolcs warned that persistent and increasing rockfall activity, combined with both long- and short-term ground swelling, may indicate a higher likelihood of a summit eruption that could generate hazardous volcanic events affecting nearby communities.

The public was advised to remain vigilant and strictly avoid entry into the six-kilometer radius Permanent Danger Zone (PDZ) due to the risk of sudden explosions, pyroclastic density currents, rockfalls, landslides, and ballistic projectiles.

Local government units were urged to prepare for possible evacuations in areas within identified hazard zones should volcanic unrest escalate further. Civil aviation authorities were also advised to caution pilots against flying near the volcano’s summit due to potential ash emissions and ballistic debris. (PNA)