The Philippine Institute of Volcanology and Seismology (Phivolcs) again observed elevated sulfur dioxide emissions from Kanlaon Volcano on Wednesday, Aug. 21, marking the second-highest recorded this year and since instrumental gas monitoring began.

In an advisory issued at 4:45 p.m. on Wednesday, Phivolcs reported that SO2 emission from the summit crater of Kanlaon Volcano had reached 6,720 tons.

It noted that Kanlaon has been degassing increased concentrations of volcanic SO2 this year at an average rate of 1,273 tons per day before the June 3 eruption.

Since then, emissions have been particularly elevated, with a current average of 3,247 tons per day. 

In addition, Phivolcs said the Kanlaon Volcano Network recorded 15 volcano-tectonic earthquakes generated by rock fracturing zero to eight kilometers beneath the northwestern sector of the edifice on Wednesday.

“Real-time ground deformation data from continuous GPS and electronic tilt measurements have been recording slow but sustained inflation (swelling) and pressurization of the edifice since March 2022, with increased inflation of the eastern flank beginning in 2023 and of the southeastern flank detected by campaign EDM in July 2024,” it also observed.

Phivolcs said the current monitoring parameters warn that shallow magmatic processes beneath the volcano are actively driving unrest, causing persistent and increasing concentrations of volcanic gas emissions, ongoing volcanic earthquake activity, and swelling of the edifice.

The public is reminded that Alert Level 2 (increasing unrest) remains in effect for Kanlaon.

This indicates ongoing unrest driven by shallow magmatic processes, with an increased chance of leading to explosive eruptions or hazardous magmatic activity from the summit crater. 

It is strongly advised to remain vigilant and avoid entering the four-kilometer-radius permanent danger zone to minimize risks from volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfalls, and others. 

In the event of ash fall affecting communities downwind of Kanlaon’s crater, Phivolcs recommended that people cover their nose and mouth with a damp, clean cloth or dust mask.

Civil aviation authorities are also asked to advise pilots to avoid flying close to the volcano’s summit, as ash and ballistic fragments from a sudden eruption can be hazardous to aircraft. 

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 if heavy rainfall over the volcano is expected or has begun.