Kanlaon Volcano's Explosive Eruption: PHIVOLCS Issues Warnings and Safety Recommendations
The Kanlaon Volcano in the Philippines experienced a moderately explosive eruption on Thursday afternoon, prompting the Philippine Institute of Volcanology and Seismology (PHIVOLCS) to issue warnings and safety recommendations. The eruption may be followed by ash emissions or similar short-lived explosive eruptions within its four-kilometer radius Permanent Danger Zone (PDZ), posing risks to nearby areas.
PHIVOLCS's bulletin, released at 11:45 p.m. on Thursday, stated that there has been no significant increase in volcanic earthquakes or ground deformation since the eruption. The institute maintained Alert Level 2, indicating a moderate level of unrest.
Volcanologists explained that this eruption could lead to further moderate-intensity activity, such as ash emissions or short-lived explosive eruptions, which may produce dangerous volcanic hazards within the PDZ. These hazards include ash dispersal over the west of the volcano and the potential for lahars in affected drainage channels.
The Kanlaon Volcano's eruption was preceded by 10 volcanic earthquakes, including seven low-frequency events associated with volcanic gas activity. However, the overall seismic activity and volcanic gas emission have been relatively low in recent weeks.
Sulfur dioxide (SO2) emission levels dropped to an extremely low average of 174 tonnes/day immediately before the eruption, with a short-term average of 752 tonnes/day recorded for the week. In comparison, the average SO2 emission since June 3, 2024, when the eruptive unrest began, was 2,823 tonnes/day.
PHIVOLCS also noted that the Kanlaon edifice has been swelling or inflating at very low and fluctuating rates since 2022 due to magma intrusion at great depths beneath the volcano. The short-term inflation began in late January 2026, preceding the Thursday eruption.
The institute's data suggests that the blockage of volcanic gas pathways and the resulting pressurization and swelling of the edifice led to the moderately explosive eruption. This mechanism has been repeating since the volcano's first moderately explosive activity in June 2024, producing similar seismic characteristics and volcanic hazards.
As a result of the eruption, towns around Kanlaon Volcano experienced ashfall, and sulfurous fumes were reported in nearby barangays. A shock wave was also generated, heard as a booming sound and felt beyond thirty kilometers from the crater. PHIVOLCS recorded the shockwave at a maximum of 225 Pascals.
PHIVOLCS recommended that communities within the PDZ remain evacuated due to life-threatening hazards such as pyroclastic density currents, ballistic projectiles, rockfalls, and volcanic gas. The agency advised local government units to prepare for subsequent evacuations in case of a hazardous worst-case explosive eruption.
Additionally, PHIVOLCS warned against the possibility of hot lahars caused by intense rains, which could erode loose ash or pyroclastic material on the upper slopes. Pilots were also advised to avoid flying close to the volcano's summit due to the risk of ash and ballistic fragments from sudden explosive eruptions.
This eruption highlights the ongoing volcanic activity and the importance of PHIVOLCS's monitoring and warning systems in ensuring the safety of nearby communities.
