Albay: The Philippine Institute of Volcanology and Seismology (Phivolcs) reported Tuesday that Mayon Volcano's ongoing effusive eruption in Albay has produced new lava flows, pyroclastic density currents (PDCs) or 'uson,' and rockfalls on its southern and eastern slopes. This came as Alert Level 3 (magmatic unrest) remains in effect for Mayon.
According to Philippines News Agency, from January 1 to February 9, a total of 1,690 PDCs, 9,941 rockfalls, and 1,346 volcanic earthquakes were recorded by the Mayon Volcano Observatory. The average sulfur dioxide emission for the period amounted to 2,466 tons per day, with a peak of 6,569 tons per day on February 4.
Since January 2025, ground deformation data have indicated that Mayon has been experiencing unstable inflation or swelling, with its eastern to northeastern flank showing extensional movement caused by deep-seated magmatic intrusions. Volcanic hazards have continually affected three major drainage systems on the southern to eastern slopes - the Mi-isi, Bonga, and Basud gullies - including minor drainages in between, all within the 6-km. radius permanent danger zone (PDZ).
As of February 8, lava flows had advanced to radial distances of 1.3 km., 1.6 km., and 3.8 km. along the Mi-isi, Bonga, and Basud gullies, respectively, while rockfall and PDC runouts remained within 3 km. of the summit crater. Phivolcs reminded residents within the 8-km. extended zone, particularly on the southern and eastern slopes of Mayon, to be prepared for possible evacuation if monitoring parameters suddenly escalate and the alert level is raised to 4. Increased vigilance against lahars and sediment-laden streamflow in channels draining the edifice is also advised during heavy rainfall over the summit area. Civil aviation authorities must also advise pilots to avoid flying close to the volcano's summit, as ash from any sudden eruption can be hazardous to aircraft.
Meanwhile, Phivolcs has also announced the lowering of Bulusan Volcano's status from Alert Level 1 (low-level unrest) to Alert Level 0 (normal). Bulusan Volcano has returned to relative quiescence following a general decline in monitoring parameters. Volcanic earthquakes recorded by the Bulusan Volcano Network have fallen to baseline levels of 0 to 5 per day since the first week of December 2025. Most monitored springs around the edifice have shown decreases in diffuse volcanic carbon dioxide concentrations since November 2025. However, local government units and the public are reminded not to enter the 4-km. PDZ radius near the vents on the south-southeastern slopes to prevent hazards, such as steam-driven eruptions, rockfalls, and landslides.
