The Philippine Institute of Volcanology and Seismology (Phivolcs) has detected a significant increase in seismic activity at Kanlaon Volcano over the past 24 hours.

In a notice issued at 1:15 p.m. on Wednesday, July 3, Phivolcs said that the Kanlaon Volcano Network recorded 90 volcanic earthquakes between 3 p.m. on July 2, and 12 p.m. on July 3.

Most of these earthquakes originated within a depth of 20 kilometers beneath the southeastern sector volcano, which included five volcano-tectonic events caused by rock fracturing and 85 weak low-frequency events indicating movement of volcanic fluids.

In addition, volcanic sulfur dioxide (SO2) gas emissions from the summit crater have remained persistently elevated since the eruption on June 3, averaging 3,254 tons per day and peaking at 5,083 tons on July 2.

“Ground deformation data from continuous GPS and electronic tilt measurements have been recording medium-term inflation of the Kanlaon edifice since March 2022 and a shorter-term inflation of the eastern flank since 2023, indicating slow but sustained pressurization within the volcano,” it explained.

These findings suggest magmatic processes drive current unrest, leading to “increased volcanic earthquake activity, persistently high concentrations of volcanic gas emission and swelling of the edifice.”

Phivolcs said Alert Level 2 remains in effect over Kanlaon Volcano due to the ongoing unrest.

Under Alert Level 2, Phivolcs warned of the potential for explosive eruptions driven by shallow magmatic processes.

The public is strongly advised to avoid the four-kilometer-radius permanent danger zone (PDZ) around the summit crater to minimize risks such as pyroclastic density currents, ballistic projectiles, and rockfalls.

Residents in areas downwind of Kanlaon are urged to prepare for ash fall events by covering their nose and mouth with a damp cloth or mask.

Communities residing along river systems on the southern and western slopes are advised to take precautionary measures in anticipation of heavy rainfall, which could trigger lahars and muddy streamflows.