THE Philippine Institute of Volcanology and Seismology (Phivolcs) has observed a significant increase in sulfur dioxide (SO2) emission from Kanlaon Volcano in Negros Island.
In an advisory yesterday, Phivolcs said it recorded 1,099 tons of SO2 emission from Kanlaon Volcano on Sunday, the “highest value recorded this year.”
“This is almost an order of magnitude higher than the average of 124 tons per day recorded since March 2023,” it said.
“In addition to this, real-time and continuous volcanic gas monitoring of thermal springs on the northern slopes detected for the first time volcanic SO2 concentrations beginning April 2023,” the agency added.
Phivolcs said Kanlaon Volcano recorded 141 volcanic quakes from April 1 to 30, or an average of five volcanic quakes per day.
“These earthquakes occurred at shallow depths to depths of 10 kilometers across the northern to western portions of the edifice,” it said.
Phivolcs also reported “short-term inflation” of the lower and middle slopes of the volcano since March. It said this indicates “slow pressurization within the volcano.”
“These parameters could indicate increased hydrothermal activity occurring beneath the edifice, possibly driven by degassing of even deeper magma, with increased possibilities of phreatic or steam-driven explosions occurring at the summit crater,” Phivolcs said.
Phivolcs said Kanlaon Volcano remains at Alert Level 1 (low level of volcanic unrest).
“The public and local government units are strongly advised to be vigilant and refrain from entering the four-kilometer permanent danger zone due to increased chances of sudden and hazardous phreatic eruptions occurring without warning,” Phivolcs said.
It asked civil aviation authorities to advise pilots to avoid flying close to summit of Kanlaon Volcano “as ejecta from any sudden phreatic eruption can be hazardous to aircraft.”
