Kanlaon Volcano crater glow sparks eruption fears
BACOLOD CITY—Crater glow, or “banaag,” observed with the naked eye at Kanlaon Volcano on Sunday evening may indicate an impending magmatic eruption, a Philippine Institute of Volcanology and Seismology (Phivolcs) official warned.
“We are not taking any chances because at Mayon Volcano before it erupted, there was also a crater glow,” Ma. Antonia Bornas, chief of the Phivolcs Volcano Monitoring and Eruption Prediction Division, told the Inquirer on Monday.
Netizens on Sunday evening posted photos of a red glow seen at the volcano’s crater.
Phivolcs said it will continue monitoring Kanlaon over the next several nights to determine whether the crater glow becomes sustained or intensifies.
Such a development could indicate that magma is near or at the crater, suggesting increasing magmatic unrest within days, Bornas said.
She noted that this could prompt a rise in alert status from alert level 2 to alert level 3.
Intermittent
According to Bornas, the glow observed so far has not been sustained and appears intermittent, possibly caused by superheated gas escaping from the volcano.
Donato Sermeno III, regional director of the Office of Civil Defense (OCD) in the Negros Island Region, said raising alert level 3 would require the evacuation of residents within the expanded 6-kilometer danger zone.
This would affect an estimated 14,765 families, or 73,765 individuals, across Canlaon City in Negros Oriental and Bago City, La Carlota City, La Castellana, San Carlos City, Pontevedra, and Moises Padilla in Negros Occidental, he said.
During the last alert level 3 declaration on Dec. 9, 2024, a total of 6,170 families or 18,890 individuals were evacuated.
Sermeno said a predisaster risk assessment meeting was held on Monday with concerned local government units to assess preparedness and preposition resources. The OCD is awaiting further guidance from Phivolcs.
He added that priority evacuation will be given to vulnerable groups, including the elderly and children, if necessary.
Since Nov. 4, 2024, invisible emissions of superheated volcanic gas have been intermittently detected at night using infrared and high-resolution monitoring by the Kanlaon Volcano Observatory (KVO), according to a Phivolcs advisory.
Parameters
Gas emissions have become more frequent since April 13. On Sunday around 7 p.m., the KVO first observed visible crater incandescence caused by superheated gas, followed by similar reports from netizens.
Phivolcs said this is a new development, although monitoring parameters have remained largely unchanged since Kanlaon’s last moderately explosive eruption on March 15.
Seismic activity has remained steady at about six volcano-tectonic earthquakes per day, while sulfur dioxide emissions have averaged 1,646 tons daily, increasing slightly to 2,382 tons in the past week.
Ground deformation data continues to show slow but sustained inflation of the volcanic edifice since 2022.
Phivolcs reiterated that while alert level 2 remains in effect, escalation to alert level 3 may be warranted if crater glow becomes sustained and intensifies, signaling possible magmatic eruption.
A magmatic eruption could produce life-threatening hazards such as pyroclastic density currents, lava flows, ballistic projectiles, ashfall, and rockfall.
Communities within the 4-kilometer permanent danger zone are advised to remain evacuated, while those in pyroclastic density current hazard zones should stay alert and ready for evacuations.
