Legazpi City, Jan. 6 -- 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.

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 baselin...