Kanlaon Volcano more swollen, chances of eruption higher

MANILA, Philippines – Negros Island’s Kanlaon Volcano is becoming increasingly swollen and there is a higher chance of “sudden explosive eruptions” occurring, state volcanologists warned the public on Saturday, January 11.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said in an advisory at 2 pm on Saturday that there has been “pronounced inflation or swelling of the middle to upper portion of the eastern edifice” of Kanlaon Volcano since Friday evening, January 10.

The volcano’s southeastern flank has also been inflated since the last week of December 2024, while the western flank has been deflated since the first week of January 2025.

“These ground deformation parameters are largely similar to those recorded prior to the [December 9, 2024] eruption, which was also preceded by a drop in SO2 (sulfur dioxide) emission,” Phivolcs said.

On Friday, Kanlaon’s SO2 emission averaged 5,763 tons per day, “close to average emissions” since another previous eruption on June 3, 2024, but “a significant drop” from the 2,029 tons per day recorded on Thursday, January 9.

“The overall parameters may indicate that the shallow magma conduit of the volcano is undergoing pressurization that may lead to an eruption broadly similar to the [December 9] event,” Phivolcs said. A conduit refers to a channel where magma passes through.

Given Kanlaon’s current state, there is “an increased chance for sudden explosive eruptions to occur and endanger communities at risk with life-threatening volcanic hazards,” according to Phivolcs.

The volcano has been under Alert Level 3 — referring to magmatic unrest — since its explosive eruption last December 9. Prior to this, it was placed under Alert Level 2 due to a “moderately” explosive eruption on June 3.

Phivolcs maintained that those within a 6-kilometer radius of Kanlaon must stay evacuated “due to the danger of pyroclastic density currents or PDCs, ballistic projectiles and ashfall, lava flows, rockfalls, and other related hazards.”

Lahar and muddy streamflows remain possible, too, during periods of heavy rain.

‘Take this situation seriously’

If the volcanic unrest worsens, Phivolcs might raise Alert Level 4, which would mean a hazardous eruption could happen within hours or days.

The highest alert level is Alert Level 5, which would be raised when a hazardous eruption is already in progress.

In a separate statement on Saturday, Office of Civil Defense Administrator Ariel Nepomuceno called on communities to prepare for the worst-case scenario.

“I appeal to all residents, even those outside the 6-kilometer extended danger zone, to take this situation seriously and evacuate immediately. We want no casualties in the event of an eruption,” Nepomuceno said.

“No responders will attempt to get inside the danger zones to execute rescue operations should an eruption occur. It is crucial for everyone’s safety to evacuate now,” he added.

Based on the latest data from the National Disaster Risk Reduction and Management Council, Kanlaon’s December eruption affected at least 12,227 families or 46,787 persons. The NDRRMC said P164 million worth of assistance has been provided to affected families.

The cost of damage to agriculture has reached P33.55 million. – Rappler.com