Legazpi city: The Philippine Institute of Volcanology and Seismology (Phivolcs) raised the alert status of Mayon Volcano to Level 3 on Tuesday, indicating an increased tendency toward a hazardous eruption. In a bulletin, Phivolcs said Mayon is exhibiting a magmatic eruption of a summit lava dome, with increased chances of lava flows and hazardous pyroclastic density currents (PDCs), or 'uson,' affecting the upper to middle slopes of the volcano, and possible explosive activity in days or weeks.

According to Philippines News Agency, PDCs on the Bonga (southeast) Gully began at 12:26 p.m., lasting at least 3 minutes, as indicated by the seismic record, and were emplaced within 2 km of the summit crater. In contrast, sulfur dioxide (SO2) emissions remain at baseline levels.

Short-term ground deformation data from continuous global positioning system, electronic tilt, and external device monitoring indicate persistent inflation of the eastern and southeastern slopes since June 2024. Since the volcano's status was raised from Alert Level 1 to Alert Level 2 on Jan. 1, repeated collapse of the unstable summit dome of Mayon has generated an increasing number and volume of rockfall events.

A total of 346 rockfall events and four volcanic earthquakes were recorded since Jan. 1, compared to 599 rockfall events from November to December last year. Phivolcs recommended evacuating the 6-km radius Permanent Danger Zone due to the threat of PDCs, lava flows, rockfalls, and other volcanic hazards.

Civil aviation authorities must also advise pilots to avoid flying near the volcano's summit, as ash from any sudden eruption can be hazardous to aircraft. Based on the current prevailing wind pattern, ash fall events are most likely to occur on the south side of the volcano.