Phivolcs urges vigilance vs. possible lahar from Mayon Volcano

MANILA, January 16 ------ The Philippine Institute of Volcanology and Seismology (Phivolcs) issued a lahar advisory today, urging communities in Albay to be vigilant and ready for possible lahar flow and related hazards.

Phivolcs warned that the forecast of heavy to intense rainfall along the eastern coast of southern Luzon could trigger volcanic sediment flows or lahars, as well as muddy streamflows and runoff in rivers and drainage channels around Mayon Volcano, which remains under Alert Level 3. "Heavy to intense rainfall may generate syn-eruption lahars on major channels draining the southern to eastern slopes of Mayon Volcano by incorporating loose material from new pyroclastic density current (PDC) deposits of its ongoing eruption," the advisory read.

Phivolcs said erodible PDC deposits occupy the Mi-isi, Bonga, and Basud Gullies and will likely feed generally in-channel but hot lahars in the Mi-isi and Binaan Channels in Daraga Municipality, Mabinit, Bonga, Matanag, Buyuan, and Padang in Legazpi City, and Lidong and Basud Rivers in Sto. Domingo. Hot lahars could cause scalding upon contact that could lead to serious and life-threatening injuries.

In addition, older and erodible eruption deposits on the watershed areas of the southwestern slopes of the volcano can be remobilized as non-eruption lahars in the Masarawag, Manila, and related distributary channels in Guinobatan Municipality, Phivolcs said. “Mayon lahars can threaten communities downstream of all the above channels with inundation, impacting force (when carrying boulders), burial, and wash out (even to sea off the eastern slopes),” it added.

Source: pna.gov.ph