Mayon Volcano had two “brief” lava bursts accompanied by seismic and infrasound signals in the past 24 hours, said the Philippine Institute of Volcanology and Seismology (Phivolcs) in its bulletin on Saturday, Oct. 21.
Phivolcs observed the lava bursts at 6:36 p.m. on Oct. 20 and 12:06 a.m. on Oct. 21.
It also noted that Mayon Volcano's seismic activity has slightly increased from nine volcanic earthquakes on Oct. 20 to 31 quakes, including 23 tremor events lasting one to 52 minutes, on Oct. 21.
Phivolcs said one pyroclastic density current (PDC) and 87 rockfall events were also recorded.
“The lava flows have maintained their advances to approximately 3.4 kilometers in Bonga (southeastern), 2.8 kilometers in Mi-isi (south), and 1.1 kilometers in Basud (eastern) Gullies. Rockfalls and PDCs generated by the collapse of the summit dome deposited debris still within four kilometers of the crater,” it pointed out.
Phivolcs said a hazardous eruption in the coming days or weeks is still possible as Mayon Volcano is still on Alert Level 3, which means it is "currently in a relatively high level of unrest."
It warned the public about the dangers of volcanic hazards, such as PDCs, lava flows, rockfalls, lahars, and sediment-laden streamflows. (Lizst Torres Abello)