The Philippine Institute of Volcanology and Seismology (Phivolcs) issued a lahar advisory on Thursday, July 24, to communities around Mayon Volcano amid a heavy rainfall forecast over the Bicol region due to tropical storms ‘Dante’ and ‘Emong’ combined with the southwest monsoon.
Phivolcs said the expected heavy to torrential rains could generate post-eruption lahars on major channels draining Mayon by incorporating loose material from remnant pyroclastic density current (PDC) deposits of the 2018 and 2023 eruptions.
The bulk of erodible PDC deposits occupies the watershed areas of the Miisi, Mabinit, Buyuan and Basud Channels.
In addition, older and erodible eruption deposits that occupy the watershed areas on the eastern and western slopes of the edifice and can be remobilized as non-eruption lahars by erosion of banks and channel beds.
Potential lahars and sediment-laden streamflows may occur along the Miisi, Binaan, Anoling, Quirangay, Maninila, Masarawag, Muladbucad, Nasisi, Mabinit, Matanag, Basud and Bulawan Channels in Albay province.
