The Philippine Institute of Volcanology and Seismology (Phivolcs) on Sunday, Oct. 22 said a phase of increased lava effusion and a heightened number of seismic activities were observed in Mayon Volcano.
Phivolcs said there was an "abrupt intensification of incandescence" at the summit crater as captured by Mayon Volcano Observatory and Mayon Resthouse at 10:10 p.m. on Oct. 21.
Meanwhile, the Mayon Volcano Network also recorded increased seismicity from 31 to 70 volcanic earthquakes including 65 tremor events with a duration of two minutes to 4 hours and 31 minutes, said Phivolcs.
Phivolcs said there was also one Pyroclastic Density Current (PDC) event and 51 rockfall events being recorded.
The lava still flows at a length of approximately 3.4 kilometers along Bonga, 2.8 kilometers along Mi-isi, and 1.1 kilometers along Basud Gullies, said Phivolcs.
Meanwhile, the sulfur dioxide (SO2) emission has an average of 727 tons per day as of Oct. 21.
Phivolcs noted that hazardous eruptions may be expected in the following days or weeks, as Mayon Volcano remains under Alert Level 3 which means that it is "currently in a relatively high level of unrest."
Phivolcs warned the public against the danger of PDCs, lava flows, lahars, rockfalls, and sediment-laden streamflows among other volcanic hazards. (Lizst Torres Abello)