The Philippine Institute of Volcanology and Seismology (Phivolcs) on Wednesday, Jan. 14 warned that Kanlaon Volcano on Negros Island is showing heightened unrest, following a surge in volcano-tectonic earthquakes beneath its flanks.

Since Wednesday midnight, Phivolcs’ Kanlaon Volcano Network recorded 45 volcano-tectonic earthquakes, ranging from magnitude 0.6 to 3.9 at depths of 0 to 13 kilometers.

The strongest tremors were felt at intensities I to IV in La Carlota City and Bacolod City, Negros Occidental, and Canlaon City, Negros Oriental.

Phivolcs explained that these earthquakes, caused by rock fracturing, indicate rising magma or magmatic gases beneath the volcano.

Sulfur dioxide emissions from the summit crater averaged 1,248 tons per day on Jan. 13, close to the medium-term average of 1,767 tons per day since Jan. 1, but previously spiked to 4,126 tons per day on Jan. 9.

“The increase in earthquakes and gas emissions suggests renewed magma intrusion, which could lead to moderately explosive eruptions,” Phivolcs said.

Alert Level 2 remains in effect, signaling that the volcano is in a state of increased unrest.

Phivolcs warned that this could trigger short-lived steam-driven or explosive eruptions, producing hazards such as pyroclastic density currents, ashfall, rockfalls, and ballistic projectiles.

Residents within the four-kilometer permanent danger zone are advised to remain evacuated, while those within six kilometers of the summit should stay alert.

Communities near rivers and streams draining the volcano are urged to watch for lahars during heavy rainfall, and civil aviation authorities have been advised to avoid flying near the summit.