MANILA, Philippines – The sulfur dioxide (SO2) emission from Negros Island’s Kanlaon Volcano spiked to an average of 4,397 tons per day on Saturday, June 8.

“This is the highest emission this year measured by campaign survey and the second highest land-based measurement for Kanlaon,” said the Philippine Institute of Volcanology and Seismology (Phivolcs) in an advisory at 9:30 pm on Saturday.

Phivolcs noted that Kanlaon “has been degassing increased concentrations of volcanic SO2 this year at an average rate of 1,458 tons per day,” but since its eruption last Monday, June 3, the emission “has been particularly elevated at a current average of 3,347 tons per day.”

Volcanic earthquakes have also averaged at 33 per day since Monday’s eruption, while inflation or swelling of the Kanlaon edifice has been observed since March 2022.

“The overall monitoring parameters indicate that degassing of magma may be driving current unrest, causing increased volcanic gas emission, swelling of the edifice, and occasional volcanic earthquake activity,” Phivolcs said.

Kanlaon remains under Alert Level 2, which means the current unrest “could eventually lead to explosive eruptions at the summit crater.”

Phivolcs reminded the public to avoid the 4-kilometer-radius permanent danger zone surrounding Kanlaon. Potential volcanic hazards include pyroclastic density currents or PDCs, ballistic projectiles, rockfall, and ashfall.

“In case of ashfall 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,” the agency said.

Phivolcs also reiterated that volcanic sediment flows or lahars may continue to form during the rainy season, especially as the southwest monsoon or habagat brings rain to Negros Occidental and Negros Oriental. Kanlaon straddles the two provinces.

“Communities living beside river systems on the southern and western slopes, especially those that have already experienced lahars and muddy streamflows, are advised to take precautionary measures when heavy rainfall over the volcano has been forecast or has begun,” the agency said. – Rappler.com