The Philippine Institute of Volcanology and Seismology (PHIVOLCS) has advised communities surrounding the Kanlaon Volcano in Negros Island to be vigilant, especially when heavy rain falls, as the same can trigger lahar to flow downstream from the volcano.
PHIVOLCS said lahar is “one of the secondary volcanic hazards caused by the eruption,” the latest of which was on December 9, 2024.
“Lahar is a rapidly flowing thick mixture of volcanic material (ash and rocks) and water, uusually generated along river channels by extreme rainfall,” PHIVOLCS said.
In June 2024, lahar flowed in Barangay Biaknabato, La Castellana town following a phreatic eruption occurred on June 3, 2024.
PHIVOLCS said lahar has several characteristics that include that following:
- It looks like a slurry of wet concrete (which can be viscous or malapot/hagkot/lapuyat).
- It can appear dilute with more water (malabnaw/lasyaw/lasaw). It may grow in volume as it erodes and carry anything in its path such as soil, rocks, plants, and even houses.
- It can occur during and even after a volcanic eruption.
To avoid the possible impacts of a lahar flow, PHIVOLCS advises communities and local government units to take the following steps:
- Monitor local weather condition and rainfall warning
- Avoid areas near rivers and other waterways downstream of the volcano
- Take preemptive evacuation when there is continuous heavy rain
- Get updates from authorities
The Kanlaon Volcano was placed under Alert Level 3 or high level of volcano arrest since December 9.
On December 15, 2024, PHIVCOLS recorded at least 14 volcanic earthquakes at the volcano in the last 24 hours.
PHIVOLCS said the volcano emitted 3,620 tons of sulfur dioxide (SO2) on December 14, 2024 and a moderate 50-meter plume toward the west-southwest side of the volcano.
Degassing continues, PHIVOLCS said.
