The Philippine Institute of Volcanology and Seismology on Saturday, Jan. 11, warned of an abrupt increase in ground deformation at Kanlaon Volcano since Friday that could lead to another sudden eruption similar to the one that occurred in December 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 9 December 2024 event”, Phivolcs said.
Ground deformation monitoring by the Kanlaon Volcano Network (KVN) has been recording a pronounced inflation or swelling of the middle to upper portion of the eastern edifice since Friday evening, it said.
“Electronic tilt recorded by the Upper Pantao Observation station (VKUP) at 1,056 m elevation on the eastern flank of the volcano showed an abrupt and sharp increase in inflationary tilt since 7:20 p.m. Friday, indicating a sudden pressurization within the upper portions of the edifice,” Phivolcs said.
Electronic Distance Meter (EDM) measurements by the Kanlaon Volcano Observatory have been tracking inflation of the southeastern flank since the last week of December 2024 and deflation of the western flank since the first week of 2025, it said.
These ground deformation parameters are largely similar to those recorded prior to the Dec. 9 eruption, which was also preceded by a drop in SO2 emission.
Phivolcs reported that from 12 a.m. Saturday to 12 a.m. Sunday Kanlaon had 14 volcanic earthquakes, and emitted 3,511 tons of SO2.
It also emitted ash for 5 minutes starting 6:11 a.m. Sunday.
The public is reminded that Alert Level 3 (magmatic unrest) is raised over Kanlaon Volcano. There is presently an increased chance for sudden explosive eruptions to occur and endanger communities at risk with life-threatening volcanic hazards, it said.
Communities within a six-kilometer radius of the summit crater must remain evacuated due to the danger of pyroclastic density currents or PDCs, ballistic projectiles and ashfall, lava flows, rockfalls and other related hazards, Phivolcs said.
Local government units and DRRM councils must also vigilantly monitor weather conditions in case heavy rainfall occurs and generates lahars and sediment-laden streamflows in channels draining the southern flanks of the volcano, it said.
Phivolcs specifically cited barangays of La Castellana and Canlaon City that have been impacted by PDCs.
Barangays downstream, especially those that have experienced lahars and muddy streamflows in June 2024, could be affected by channel-confined lahars in case of heavy rains, it added.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft, Phivolcs said
Phivolcs also advised local government units and DRRM councils to prepare communities within the Pyroclastic Density Currents Hazard Map for potential evacuation in case unrest further escalates and a hazardous worst-case explosive eruption becomes imminent.
The Negros Occidental provincial government has prepositioned vehicles for an immediate evacuation in case of an eruption, Provincial Administrator Rayfrando Diaz.*