Kanlaon Volcano may be placed under Alert Level 3, as the Philippine Institute of Volcanology and Seismology (Phivolcs) warned of higher chances of "magmatic unrest within days" if its crater glow is sustained and intensifies.

In its advisory issued early Monday, Phivolcs noted that based on the naked-eye observation, the Kanlaon Volcano Observatory reported for the first time an incandescence at the Kanlaon Volcano summit caused by superheated volcanic gas, followed by netizen reports of the same observations.

"Such a phenomenon when it becomes visible to the naked eye is called crater glow or banaag, a common precursor of magmatic eruption at Mayon Volcano," it stated.

"While this is a new development, monitoring parameters have persisted in approximately the same level after Kanlaon’s last moderately explosive eruption on 15 March 2026," it added.

Phivolcs said the seismicity of the Kanlaon remained at the steady rate of six volcano-tectonic earthquakes per day, while sulfur dioxide gas emissions averaged 1,646 tonnes per day and have increased only slightly to 2,382 tonnes per day this past week.

"Ground deformation parameters have been non-steady but still indicate a sustained and slow-rate inflation of the volcano edifice since 2022," it added.

"Nonetheless, if crater glow becomes sustained and intensifies, this would indicate that magma is close or at the crater and could warn of increasing chances of magmatic unrest within days," Phivolcs warned.

It also reminded the public that while Alert Level 2 prevails over Kanlaon, "the alert status may step up to Alert Level 3 should magmatic eruption be forewarned by sustained and intensifying crater glow or banaag at the summit crater."

Phivolcs also stressed that "magmatic eruption would generate life-threatening volcanic hazards such of pyroclastic density currents or PDCs, lava flows, ballistic projectiles, ashfall, rockfall and others" while communities within the 4-km radius Permanent Danger Zone or PDZ were strongly recommended to "strictly remain evacuated and those within the PDC Hazard Zones be vigilant and ready for evacuation in case the chances of magmatic eruption increase." Robina Asido/PHS