Phivolcs detects Kanlaon’s highest gas flux

By Glazyl Y. Masculino

BACOLOD CITY — The Philippine Institute of Volcanology and Seismology (Phivolcs) has issued a notice of elevated volcanic sulfur dioxide (SO2) gas emission from Kanlaon volcano.

In its June 8 advisory at 9:30 p.m., Phivolcs reported that sulfur dioxide gas emission from the summit crater of Kanlaon averaged 4,397 tonnes per day, based on campaign Flyspec measurements last Saturday.

This marks the highest emission recorded this year by campaign survey and the second highest land-based measurement for Kanlaon.

The public is strongly advised to remain vigilant and avoid the four-kilometer-radius Permanent Danger Zone (PDZ) to minimize risks from volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfall, and others. Kanlaon volcano remains under Alert Level 2.

Under this alert level, Phivolcs explained that shallow magmatic processes currently drive unrest, which could eventually lead to explosive eruptions at the summit crater.

According to Phivolcs, the volcano has been emitting increased concentrations of volcanic sulfur dioxide this year at an average rate of 1,458 tonnes per day.

Since the eruption on June 3, emissions have been particularly elevated, with a current average of 3,347 tonnes per day.

Additionally, volcanic earthquakes have persisted at an average of 33 events per day since the eruption.

Phivolcs also recorded medium-term inflation of the Kanlaon edifice since March 2022 and shorter-term inflation of the eastern flank since 2023. This indicates slow pressurization within the volcano, based on ground deformation data from continuous GPS and electronic tilt measurements.

Overall monitoring parameters suggest that magma degassing may be driving the current unrest, leading to increased volcanic gas emission, swelling of the edifice, and occasional volcanic earthquake activity, according to Phivolcs.

Communities living near river systems on the southern and western slopes, especially those that have already experienced lahars and muddy streamflows, are advised to take precautionary measures during heavy rainfall.

Civil aviation authorities have also directed pilots to avoid flying close to the volcano’s summit, as ash and ballistic fragments from sudden eruptions can be hazardous to aircraft.

As of 12 a.m. June 9, Phivolcs recorded 17 volcanic earthquakes, with a steaming plume reaching 500 meters high from Mt. Kanlaon.

Meanwhile, Mayor Rhummyla Nicor-Mangilimutan reminded the people of La Castellana in Negros Occidental to remain vigilant following the spread of false information on social media regarding the alert status of the volcano, which caused panic among residents last Thursday.

In response, Mangilimutan issued an executive order directing all municipal employees to refrain from giving media interviews and disseminating unverified information regarding the Kanlaon eruption.

She emphasized that as the local chief executive, she is the only authorized spokesperson for media interviews to ensure transparency and accuracy of information.

For updates on Mt. Kanlaon, Mangilimutan authorized Police Major Rhojn Darell Nigos, La Castellana police chief; John BF De Asis of the Municipal Disaster Risk Reduction and Management Office (MDRRMO); and Emily Tan of the Municipal Social Welfare and Development Office (MWSDO) as her representatives.

Mangilimutan stressed in the executive order that “this is to avoid false information, fake news, and to avoid confusion and panic among the public.”

In a Facebook live stream, Mangilimutan reiterated that Kanlaon volcano remains under Alert Level 2 and explained the danger and threat of lahar to barangays at the volcano’s foot.

She said forced evacuation was imposed due to the unpredictable situation and heavy rains. The mayor urged residents not to be complacent, as the volume of lahar that could be washed away by heavy rains is unknown.

“This is part of our preemptive measures,” she added.

While Kanlaon volcano remains under Alert Level 2, she advised residents to stay alert and remain at evacuation centers.

The city of Bacolod has extended P1 million in relief assistance to affected residents, while Victorias Mayor Javier Miguel Benitez provided P100,000 in financial aid.

Bacolod Mayor Alfredo “Albee” Benitez and his son Mayor Javier Miguel visited the town last Saturday to personally deliver assistance and water to evacuees.

They also visited Barangay Biak na Bato, the hardest hit area in the town due to lahar.