The Mayon Volcano Network recorded 34 volcanic earthquakes including a one-minute volcanic tremor, said the Philippine Institute of Volcanology and Seismology (Phivolcs) on Thursday, Sept. 28.
Phivolcs said that 144 rockfall events and one Pyroclastic Density Current (PDC) event also occurred.
Meanwhile, Phivolcs recorded sulfur dioxide (SO2) emissions at an average of 875 tons per day on Sept. 27.
Moreover, there was slow lava flow effusion at the length of 3.4 km along Bonga; 2.8 km along Mi-isi; and 1.1 km along Basud Gullies while the lava collapsed up to 4 km from the crater, said Phivolcs.
Phivolcs said that Mayon Volcano remained under Alert Level 3 which means that it is in a "relatively high level of unrest" with the possibility of hazardous eruption in the following days or weeks.
Phivolcs advised the public to remain evacuated from the 6-km radius Permanent Danger Zone (PDZ) and to exercise vigilance against PDCs, lava flows, rockfalls, lahars, sediment-laden streamflows, and other volcanic hazards. (Lizst Torres Abello)