State volcanologists have raised Alert Level 3 over Mayon Volcano in Albay after pyroclastic density currents (PDCs), locally known as “uson,” were observed, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).
PHIVOLCS said the alert signifies an “increased tendency toward a hazardous eruption.” The PDCs were generated when newly extruded lava collapsed along the Bonga (southeast) Gully at around 12:26 p.m., lasting at least three minutes and reaching up to two kilometers from the summit crater based on seismic records.
Under Alert Level 3, volcanologists noted heightened unrest, including frequent rockfall events, seismic swarms with low-frequency earthquakes or harmonic tremor, possible ground deformation, and changes in volcanic gas or crater activity. If these trends persist, a dangerous eruption could occur within days or weeks.
PHIVOLCS warned that Mayon is showing magmatic activity at the summit lava dome, raising the likelihood of lava flows, hazardous PDCs affecting the upper to middle slopes, and possible explosive eruptions. Evacuation is advised within the 6-kilometer Permanent Danger Zone (PDZ) due to risks from PDCs, lava flows, and rockfalls. Local authorities in Camalig announced evacuations within the PDZ starting Tuesday afternoon.
Aviation authorities were also advised to keep aircraft away from the summit because volcanic ash poses serious hazards to flights. PHIVOLCS recorded 85 rockfall events in the past 24 hours and said the current unrest resembles the 2023 Mayon eruption, which lasted several months, though officials noted activity could still weaken or stop at any time.
