By JEN BAYLON
Kanlaon Volcano’s explosive eruption early yesterday morning was not a major one expected, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
“There is an expectation of a bigger explosion, but we do not yet know when it will happen,” Phivolcs Research Specialist 1 Pearly Sianson said yesterday.
Kanlaon erupted with a minor explosive ashing event at 5:51 a.m. yesterday, producing a voluminous bent plume approximately 4,000 meters tall that drifted southwest.
The eruption lasted for almost one hour until 6:47 a.m., Phivolcs reported.
“This is a minor explosive eruption, one of the expected events under Alert Level 3,” Sianson added.
The volcano also emitted 1,655 tons of sulfur dioxide, according to the agency’s advisory yesterday.
Phivolcs warned that while Kanlaon did not spew lava, the recent volcanic event “may be followed by similar short-lived explosive eruptions in the short term or even progress to lava eruptions that generate lava flows and lava fountaining activity.”
“If the eruption becomes stronger, it could impact the [communities surrounding Kanlaon],” Sianson said.
Phivolcs said pyroclastic density currents (PDCs) descended the slopes on the general southern edifice based on IP and thermal camera monitors following the eruption.
“We observed PDCs — hot gases and rocks — extending about 0.8 kilometers from the crater,” Sianson said.
The volcano remains under Alert Level 3, indicating magmatic unrest that could generate similar ash emissions and short-lived explosive eruptions in the short term, posing life-threatening volcanic hazards.
The recent eruption — the third in a series of volcanic events since last year — was comparable to the explosive eruption on December 9, 2024, Phivolcs said.
Ashfall, sulfur odor
The eruption yesterday resulted in ashfall in Negros Occidental cities of La Carlota and Bago, as well as La Castellana town.
According to monitoring data from the Provincial Disaster Risk Reduction and Management Council, 13 barangays in La Carlota, including Ara-al, Yubo, San Miguel, Haguimit, La Granja, Cubay, Nagasi, Balabag, and Roberto S. Benedicto, experienced ashfall.
All three Poblacion areas reported light ashfall, the data added.
In La Castellana, volcanic ash was reported in Sag-ang and the upper barangays, where residents also reported a light sulfur smell.
Face mask distribution was initiated in both La Carlota and La Castellana.
In Pontevedra town, two barangays — Zamora and Gomez — also experienced light ashfall, prompting ongoing road flushing operations led by the Bureau of Fire Protection.
Meanwhile, 24 barangays in Hinigaran town were affected by varying intensities of ashfall.
Sianson said several areas experienced a strong sulfuric smell, such as Bago’s Barangays Mailum, Ilihan, Binubuhan, and even at the Phivolcs observatory in Barangay Cubay, along with a slight sulfuric odor in Hinigaran town.
Classes suspended
In response to the eruption, all face-to-face classes at all levels in La Carlota were suspended yesterday, Mayor Rex Jalando-on said in his executive order.
Work in all government offices in the city has been suspended until further notice, although offices involved in disaster and emergency response will remain operational.
Private establishments are encouraged to suspend work in support of public safety efforts, the order said.
In La Castellana, Mayor Rhummyla Nicor-Mangilimutan also declared the suspension of classes at all levels until further notice.
In Pontevedra, the Municipal Disaster Risk Reduction and Management Office also announced the suspension of classes.
The city governments of Bago and San Carlos, likewise, suspended face-to-face classes yesterday, with schools shifted to modular learning.
Vigilance
Donato Sermeno III, regional director of the Office of Civil Defense in the Negros Island Region, emphasized the importance of continued vigilance amid the volcanic threat.
“We cannot relax our efforts and preparations, especially if the alert level escalates,” Sermeno stressed.
The Regional Task Force Kanlaon directed all concerned local government units to suspend the entry of residents to Kanlaon’s six-kilometer permanent danger zone following the eruption.
The pressing need for potable water in affected areas remains a priority, with ongoing efforts to address this and other immediate needs.
Meanwhile, Phivolcs said local government units near Kanlaon must prepare for subsequent evacuation in case the unrest further escalates and a hazardous worst-case explosive eruption becomes imminent.
“Increased vigilance must be exercised should intense rains occur since loose ash or pyroclastic material has been deposited in the upper slopes and could easily be eroded to generate lahars and sediment-laden streamflows in channels draining the southern and western portions of the edifice,” Phivolcs said in an advisory./ With reports from ABS-CBN News, PNA / JB, WDJ