Mount Kanlaon emitted 1,099 tonnes of volcanic sulfur dioxide (SO2), the highest so far this year, on Sunday, April 30, the Philippine Institute of Volcanology and Seismology (Phivolcs) advised on Monday morning, May 1. Courtesy of Phivolcs "Volcanic sulfur dioxide (SO2) gas emission from the summit crater of Kanlaon based on campaign Flyspec measurements yesterday, 30 April 2023, averaged 1,099 tonnes/day, the highest value recorded this year. This is almost an order of magnitude higher than the average of 124 tonnes/day recorded since March 2023," said the agency. The volcanic SO2 was first detected in early April. "The Kanlaon Volcano network recorded one hundred and forty-one (141) volcanic earthquakes between 1 April and 30 April 2023, for an average of five (5) per day. These earthquakes occurred at shallow depths to depths of 10 kilometers across the northern to western portions of the edifice," Phivolcs said. Also, data gathered through the Global Positioning System and electronic tilt meters showed that the volcano's lower and middle slopes had been slowly swelling since March. This indicates slow pressurization inside the volcano, said Phivolcs. "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," it warned. The agency also reminded that Alert Level 1 prevails over Mt. Kanlaon and the public and local government units need to be vigilant and refrain from entering the four-kilometer permanent danger zone due to increased chances of sudden and hazardous phreatic eruptions. "Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ejecta from any sudden phreatic eruption can be hazardous to aircraft. DOST-PHIVOLCS is closely monitoring Kanlaon Volcano’s activity and any new development will be relayed to all concerned," it added.