PHIVOLCS issues lahar advisory for Mayon, Kanlaon amid Verbena, shearline rains

Lahar flow may be experienced in areas near Mayon Volcano in Albay and Kanlaon Volcano in Negros Island amid the rains from Tropical Depression Verbena and the shear line, the PHIVOLCS said on Monday.

Mayon

“These rains could generate volcanic sediment flows or lahars, muddy streamflows or muddy run-off in rivers and drainage areas on Mayon Volcano,” the PHIVOLCS said in an advisory.

“DOST-PHIVOLCS thus strongly recommends increased vigilance, readiness, and if necessary, pre-emptive evacuation of communities in pre-determined zones of lahar and related hazards in the Province of Albay,” 

Life-threatening post-eruption lahars may happen during intense to torrential rainfall on major channels. 

Communities near Miisi, Binaan, Mabinit, Buyuan, Anoling, Matanag, Bonga, and Basud Channels could be severely threatened by post-eruption lahars.

Non-eruption lahars could severely threaten communities in Guinobatan town amid intense rains over Masarawag and Maninila Channels and even creeks within their immediate vicinities.

“Mayon lahars, which are characteristically strong enough to transport enormous volumes of gravel and boulders, have historically and continues to threaten communities by their force of impact, inundation, burial and wash out to sea,” PHIVOLCS said.

“DOST-PHIVOLCS strongly advises the communities and local government units of the above identified areas of risk to continually monitor the rainfall conditions and take pre-emptive response measures for their safety,” it added.

Kanlaon

Meanwhile, PHIVOLCS also warned of possible lahars in areas near Kanlaon Volcano.

“This can generate volcanic sediment flows or lahars, sediment-laden streamflows or muddy run-off and related siltation in rivers and drainage areas on Kanlaon Volcano, which is currently at Alert Level 2,” PHIVOLCS said.

“DOST-PHIVOLCS thus strongly recommends increased vigilance and readiness of communities in pre-determined zones of lahar and related hazards on this volcano,” it added.

Life-threatening lahars and sediment-laden streamflows are possible on major channels on the southern, western and eastern slopes of Kanlaon Volcano during prolonged heavy to intense rainfall.

During intense rainfall, post-eruption lahars may occur from remnant pyroclastic density current (PDC) deposits of the October 24 explosive eruption, loose ashfall, as well as recent ash emission events.

Non-eruption lahars can be generated when areas on the upper slopes that have been recently exposed by landslides or weakened during the passage of Typhoon Tino earlier this month become susceptible to failure and feed debris to rivers that have already delivered destructive flows to downstream communities, PHIVOLCS said.

Communities of Bago City, La Carlota City, La Castellana, Moises Padilla and San Carlos City, Negros Occidental and Canlaon City, Negros Oriental that are situated along the following channels may be affected:

• Ibid River
• Cotcot River
• Talaptapan River
• Malaiba River
• Panubigan Creek
• Buhangin – Indurayan River
• Najalin River
• Inyawan River
• Maragandang River
• Panun-an Creek
• Intiguiwan River
• Camansi River
• Maao River
• Tokon-tokon River
• Masulog River
• Binalbagan River
• Taco Creek
• Linothangan River

According to PHIVOLCS, these communities and those further downstream of these channels are advised to be prepared in case evacuation becomes necessary and to avoid traversing affected streams even those farther downslope of the volcano. 

“Kanlaon lahars, which were shown by Typhoon Tino to be strong enough to transport enormous volumes of gravel and boulders, could threaten communities by their force of impact, inundation, burial and wash out,” PHIVOLCS said.

“DOST-PHIVOLCS strongly advises the communities and local government units of the above identified areas of risk to continually monitor the rainfall conditions and take pre-emptive response measures for their safety,” it added. –NB, GMA Integrated News