Eruption Data: A moderately explosive eruption occurred at the summit crater of Kanlaon Volcano at 05:51 AM today, 8 April 2025, that lasted fifty-six (56) minutes based on seismic and visual recordings. The eruption generated a gray voluminous plume that slowly rose to 4,000 meters above the vent before bending and drifting west and southwest. Audible rumbling sounds of the eruption were reported in Brgys. Biak-na-Bato and Sag-ang, La Castellana, Negros Occidental and Brgy. Pula, Canlaon City, Negros Oriental. Pyroclastic density currents or PDCs descended the southern slopes within a kilometer of the crater, in the jurisdiction of La Castellana, based on visual and thermal camera monitoring. Large ballistic fragments were also observed to have been thrown around the crater within a few hundred meters and caused burning of vegetation near the volcano summit. Thin ashfall has been reported in the following localities of Negros Occidental: La Carlota City– Brgys. Roberto Salas Benedicto, La Granja, Haguimit, Nagasi, Yubo, Ara-al, San Miguel and Cubay; Bago City– Brgys. Mailum, Ilijan, and Binubuhan, and; La Castellana– Brgys. Sag-ang and Mansalanao. Sulfurous fumes were also experienced strongly in Brgy. Cubay, La Carlota City and faintly as far as the Municipality of Hinigaran, Negros Occidental.
Monitoring Data Prior to the Eruption: The eruption was preceded by short-term inflation or swelling of the southeastern edifice that began in 10 January 2025 and by a decline in average sulfur dioxide or SO2 emission from 4,014 tonnes/day since 3 June 2024 to 2,453 tonnes/day since 1 March 2025. SO2 emission yesterday averaged only 1,655 tonnes/day. There was no significant change in the average occurrence of volcanic earthquakes of 14 events/day since 3 June 2024. These parameters indicate that the blockage of volcanic gas emission (or closed-system degassing) and resulting pressurization and swelling of the edifice drive moderately explosive eruption at Kanlaon.
Current Outlook: No pronounced increases in volcanic earthquake, ground deformation or volcanic gas parameters have followed the eruption as of present. Alert Level 3 (magmatic unrest) therefore remains over Kanlaon Volcano. This means that this morning’s explosive eruption may be followed by similar short-lived explosive eruptions in the short term or even progress to lava eruptions that generate lava flows and lava fountaining activity.
Recommendations: It is recommended that communities within a 6-km radius of the summit crater remain evacuated due to the danger of potential pyroclastic density currents or PDCs, ballistic projectiles, rockfalls, ashfall and other related hazards that could be posed by similar explosive eruptions. Local government units must also prepare their communities within the PDC hazard zone for subsequent evacuation in case unrest further escalates and hazardous worst-case explosive eruption becomes imminent. Increased vigilance must be exercised should intense rains occur since loose ash or pyroclastic material have been deposited in the upper slopes and could easily be eroded to generate lahars and sediment-laden streamflows in channels draining the southern and western portions of the edifice. 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.
DOST-PHIVOLCS maintains close monitoring of Kanlaon Volcano and any new development will be communicated to all concerned stakeholders.
DOST-PHIVOLCS
