ILOILO CITY — The Philippine Institute of Volcanology and Seismology (Phivolcs) has reported a significant increase in seismic activity at Kanlaon Volcano on Negros Island.

Phivolcs on Sunday said it recorded a total of 24 volcano-tectonic earthquakes in the stratovolcano.

Mt. Kanlaon in Negros Island - PNA-Bacolod file photo Mt. Kanlaon. PHIVOLCS FILE PHOTO Mt. Kanlaon. PHIVOLCS FILE PHOTO Kanlaon rice terraces

"These earthquakes ranged in energy from local magnitude 0.8 to 2.3 and occurred at depths of 0 to 6 kilometers beneath the western flank of the Kanlaon volcanic edifice," the Phivolcs said.

The increased seismic activity has coincided with a notable rise in the volcanic sulfur dioxide gas emissions from the summit crater, which averaged 2,003 tonnes per day on May 26, up from an average of 1,291 tonnes per day on January 1 this year.

"Ground deformation data from continuous GPS and electronic tilt measurements have been recording an ongoing inflation that began between April and July 2023 and a longer-term inflation of the entire edifice since March 2022," it added.

The Phivolcs also said that recent monitoring parameters have been consistent with shallow hydrothermal activity driven by the degassing of deeper magma. However, the current volcano-tectonic earthquake activity indicates shallow rock fracturing within the edifice, which "may lead to further unrest."

Alert Level 1 or low level of unrest has been maintained over Kanlaon, but Phivolcs warned that the volcano's status may be raised to Alert Level 2 (moderate level of unrest) should the current trends persist.

The public and local government units are urged to remain vigilant and avoid entering the four-kilometer permanent danger zone due to the heightened risk of sudden and hazardous phreatic eruptions.

Civil aviation authorities have also been advised to instruct pilots to avoid flying near the volcano's summit, as volcanic ejecta can pose significant hazards to aircraft.