Increased ground deformation was recorded at Kanlaon Volcano in Negros Island, according to PHIVOLCS advisory at 2 p.m. on Saturday, January 11, 2025.

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 evening on January 10, 2025, PHIVOLCS said.

Electronic tilt recorded by the Upper Pantao Observation station (VKUP) at 1,056 meters elevation on the eastern flank of the volcano showed an abrupt and sharp increase in inflationary tilt since 7:20 p.m. on January 2025, indicating a sudden pressurization within the upper portions of the edifice.

Electronic Distance Meter (EDM) measurements by Kanlaon Volcano Observatory have been tracking inflation of southeastern flank since the last week of December 2024 and deflation of the western flank since the first week of 2025. These ground deformation parameters are largely similar to those recorded prior to the December 9, 2024 eruption, which was also preceded by a drop in sulfur dioxide (SO2) emission.

Campaign SO2 measurements on January 10, 2025, averaged 5,763 tons a day close to average emissions since the June 3, 2024 eruption, but a significant drop to 2,029 tons per day was recorded on January 9, 2025.

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 December 9, 2024 event.

The public is reminded that Alert Level 3 (magmatic unrest) prevails 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. 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. Local government units and disaster risk reduction and management councils (DRRMC) must also monitor vigilantly weather conditions in case heavy rainfall occurs and generates lahars and sediment-laden streamflows in channels draining the southern flanks of the volcano. Specifically, barangays of La Castellana town in Negros Occidental and Canlaon City in Negros Oriental have been impacted by PDCs, as well as barangays downstream of these especially those that have experienced lahars and muddy streamflows in June 2024, could be affected by channel-confined lahars of in case of heavy rains, the advisory also said.

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. Lastly, local government units and DRRM councils are advised to prepare communities within the DOST-PHIVOLCS Pyroclastic Density Currents Hazard Map for potential evacuation in case unrest further escalates and hazardous worst-case explosive eruption becomes imminent, the advisory further said.