The Philippine Institute of Volcanology and Seismology (Phivolcs) urged the public on Friday to increase vigilance against possible lahar from Mayon Volcano.
In an advisory, the Phivolcs said that based on forecast, the shear line could cause continued potentially high-volume rainfall across the Bicol region. Further, heavy to intense rainfall is expected over the Albay province in the coming days.
This could generate volcanic sediment flows or lahar, muddy streamflows or muddy run-off in rivers and drainage areas, the Phivolcs said.
It added prolonged and heavy rainfall may also generate post-eruption lahars on major channels draining Mayon Volcano by incorporating loose material from remnant pyroclastic density current (PDC) deposits from the January to March 2018 and June to December 2023 eruptions.
“The bulk of erodible PDC deposits occupy the watershed areas of the Mi-isi, Mabinit, Buyuan, Bonga, and Basud Channels. In addition, older and erodible eruption deposits on the watershed areas of the eastern and western slopes of the edifice and can be remobilized as non-eruption lahars by erosion of banks and channel beds,” the advisory reads.
This could threaten communities downstream of the above channels with inundation, burial, and wash away.
Potential lahars and sediment-laden streamflows may occur along the Miisi, Binaan, Anoling, Quirangay, Maninila, Masarawag, Muladbucad, Nasisi, Mabinit, Matan-ag, Buyuan, Basud, and Bulawan Channels in Albay province, the Phivolcs said. (PNA)