Heavy rain may cause lahar on Negros Island — PHIVOLCS

MANILA, Philippines — Heavy thunderstorms over Negros Island could trigger lahars, or volcanic mudflows, around the southern slopes of Mount Kanlaon, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) warned on Thursday. 

In an advisory issued midnight, PHIVOLCS called on Negros residents, especially those residing in communities along rivers draining southern Kanlaon, monitor weather conditions and take pre-emptive measures. 

“Lahar can threaten communities along the middle and lower slopes with inundation, burial and wash out,” the agency said. 

PHIVOLCS also reported that Wednesday’s downpour caused volcanic sediment flows on the southern slopes of Kanlaon. Lahars were first observed around 1 p.m. and lasted for 25 minutes. 

It said that gray and cohesive mud, plant debris, and gravel were deposited by lahars in four waterways:

PHIVOLCS said that volcanic mudflows remained mostly within their channels, except along Tamburong Creek.

“Flows along Tamburong Creek overflowed and dumped a few centimeters of deposit on a stretch of the main road in Biak-na-Bato, rendering this impassable to motorists,” it said. 

Kanlaon was placed under Alert Level 2, indicating increasing unrest, after the volcano spewed a five-kilometer high ash cloud into the sky on Monday evening. 

PHIVOLCS recorded 27 volcanic earthquakes at Kanlaon in the 24 hours. The volcano also sent a 1.5-kilometer high ash plume into the sky. 

The “explosive” eruption of Kanlaon forced the evacuation of around 1,669 people in Negros Occidental and Negros Oriental. 

The government has provided P2.1 million in assistance to affected residents.