• GILBERT P. BAYORAN
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported a significant increase in seismic activity at Kanlaon Volcano on Thursday, warning that the unrest signals progressive rock fracturing beneath the volcano as magma or magmatic gas moves toward the surface.
Between midnight and 5 p.m. on Oct. 1, the Kanlaon Volcano Network recorded 28 volcano-tectonic (VT) earthquakes ranging from magnitude 0.9 to 1.8. The quakes occurred at depths of zero to 11 kilometers beneath the volcano’s western flanks.
PHIVOLCS said the increase in VT earthquakes, caused by rock-fracturing processes, was accompanied by a sustained and voluminous degassing plume from the summit crater beginning at noon. Sulfur dioxide (SO₂) emissions also remained elevated.
The agency noted that the combination of intensified degassing and increased VT earthquakes suggests that significant volcanic gas at depth may be forcing its way upward through the volcanic edifice.
Kanlaon remains under Alert Level 2, indicating a “state of increased unrest.”
PHIVOLCS cautioned that the heightened activity could trigger steam-driven or phreatic eruptions, as well as short-lived weak to moderately explosive eruptions.
Such events may generate life-threatening hazards including pyroclastic density currents, ballistic projectiles, ashfall, and rockfall.
Communities within the 4-kilometer Permanent Danger Zone are advised to remain evacuated, while residents within a 6-kilometer radius of the summit crater are urged to stay vigilant and prepare for possible escalation of volcanic activity.
PHIVOLCS also warned of potential syn-eruption lahars and sediment-laden streamflows along channels draining the volcano, particularly during periods of heavy rainfall.
Civil aviation authorities were advised to caution pilots against flying close to Kanlaon’s summit, as ash from sudden eruptions could pose hazards to aircraft. | GPB
