The Philippine Institute of Volcanology and Seismology (PHIVOLCS) recorded nine pyroclastic density current signals, or “uson,” and 428 rockfall events from Mayon Volcano over the past 24 hours as of Sunday, 18 May.
PHIVOLCS also logged 20 volcanic earthquakes and 19 volcanic tremors lasting a total of 127 minutes. Daily sulfur dioxide emissions from the volcano reached 1,771 tons on Sunday.
Lava effusion and lava flows were observed in the Basud (3.8 kilometers), Bonga (3.2 kilometers), and Mi-isi (1.6 kilometers) gullies.
A fair crater glow was observed, while weak plume emissions drifting southwest were also noted.
According to PHIVOLCS, possible hazards include rockfalls or landslides, ballistic fragments, lava flows and lava fountaining, moderate-sized explosions, pyroclastic density currents, and lahars during heavy and prolonged rainfall.
Mayon Volcano remains under Alert Level 3 due to intensified unrest and ongoing magmatic activity, PHIVOLCS said.