The Philippine Institute of Volcanology and Seismology (Phivolcs) warned of elevated volcanic sulfur dioxide (SO₂) gas flux at Kanlaon Volcano on Saturday, Aug. 24.
In an advisory, Phivolcs reported that SO₂ gas emission from the summit crater of Kanlaon has reached 6,367 tons per day.
“This is the third-highest emission from the volcano recorded this year and since instrumental gas monitoring began,” Phivolcs said.
Phivolcs explained that SO₂ fumes were also reported in several barangays of Murcia, Negros Occidental.
Kanlaon, Phivolcs explained, has been “degassing increased concentrations of volcanic SO₂” this year at an average rate of 1,273 tons per day before the eruption on June 3, 2024.
However, Phivolcs noted that “emissions since then have been particularly elevated” at a current average of 3,295 tons per day.
Steam-rich plumes
Phivolcs also noted that “strong degassing activity from the summit crater” generated voluminous steam-rich plumes that rose 700 meters before drifting north.
State seismologists also warned that volcanic earthquake activity persists at an average of nine events per day since the eruption.
“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,” Phivolcs explained.
Phivolcs also observed that the current monitoring parameters indicate shallow magmatic processes beneath the volcano, which are actively contributing to unrest.
This includes persistent and increasing volcanic gas emissions, ongoing volcanic earthquake activity, and swelling of the volcano’s structure.
Increasing unrest
Amid these developments, Phivolcs reminded that Alert Level 2 or “increasing unrest” prevails over Kanlaon.
“This means that there is current unrest driven by shallow magmatic processes with increased chances of leading to explosive eruptions or even hazardous magmatic eruptions from the summit crater,” Phivolcs said.
Phivolcs strongly urged the public to remain "vigilant" and avoid entering the four-kilometer-radius Permanent Danger Zone (PDZ) to reduce risks from volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfalls, and other potential dangers.
“In case of ash fall events that may affect communities downwind of Kanlaon’s crater, people should cover their nose and mouth with a damp, clean cloth or dust mask,” Phivolcs said.
Furthermore, Phivolcs said civil aviation authorities should instruct pilots to “avoid flying near the volcano’s summit” as ash and ballistic fragments from a sudden eruption could pose serious hazards to aircraft.
Phivolcs also advised communities residing along river systems on the southern and western slopes, particularly those that have previously encountered lahars and muddy streamflows, to “take precautionary measures” when heavy rainfall is forecasted or has already begun.