The Philippine Institute of Volcanology and Seismology (Phivolcs) said Kanlaon Volcano again emitted dark ash plumes at 11:45 a.m. on Monday, Dec. 23, following its explosive eruption on Dec. 9.

The ash plume rose to about 1.2 kilometers and drifted northwest, affecting communities in Negros Occidental.

Accompanying the ash emission, weak and low-frequency volcanic earthquakes were also recorded, indicating ongoing volcanic unrest.

Authorities have issued warnings for residents in areas downwind of the ash emission, as ashfall is expected to reach communities located northwest and west of the volcano.

Despite the ash emission, Phivolcs said other volcanic parameters remain elevated but unchanged.

The agency reiterated that Alert Level 3 (magmatic unrest) remains in effect due to the increased risk of sudden and stronger explosive eruptions, which could endanger nearby communities with life-threatening volcanic hazards.

Communities within a six-kilometer radius of the summit crater are urged to remain evacuated due to the dangers of pyroclastic density currents (PDCs), ballistic projectiles, ashfall, lava flows, rockfalls, and other related hazards.

Local government units and disaster risk and reduction management (DRRM) councils are also urged to monitor weather conditions closely.

In the event of heavy rainfall, Phivolcs said lahars and sediment-laden streamflows may form in channels draining the volcano’s southern flanks.

Barangays in La Castellana and Canlaon City, as well as other downstream areas that were affected by lahars and muddy streamflows in June, are at risk for channel-confined lahars if heavy rains occur, it added.

Civil aviation authorities have also been advised to restrict pilots near the volcano’s summit, as ash from any sudden eruption could pose a serious hazard to aircraft.

Local government units and DRRM councils are advised to prepare for potential evacuations in communities identified in the Pyroclastic Density Currents Hazard Map in case volcanic unrest escalates further, and a worst-case explosive eruption becomes imminent.