Kanlaon Volcano emits ash anew, alert level remains

By Dolly Yasa

BACOLOD CITY — Kanlaon Volcano spewed ash again on Tuesday, September 10, with a 30-minute emission that produced a grayish plume rising about 600 meters above the summit crater.

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported Wednesday that this was the second ash emission recorded since September 8.

Despite the recent activity, Alert Level 2 remains in effect, according to Ptolemy Man̈ego, science research assistant at the Kanlaon Volcano Observatory.

Entry into the four-kilometer permanent danger zone surrounding the volcano remains strictly prohibited.

Man̈ego said no accompanying seismic activity was detected during both ash emission events.

PHIVOLCS personnel have been deployed to the municipalities of Murcia and Don Salvador Benedicto to monitor for possible ashfall, as the plume drifted toward these areas.

Meanwhile, the Civil Aviation Authority of the Philippines (CAAP) issued a Notice to Airmen (NOTAM) effective September 10 to 11, advising pilots to avoid flying near the volcano, with restrictions in airspace up to 10,000 feet.

CAAP warned of possible hazards from sudden eruptions and ashfall.

PHIVOLCS had earlier downgraded Kanlaon’s status from Alert Level 3 to Level 2 on July 29, 2025, indicating a shift from high-level unrest to moderate volcanic activity.

This downgrade allowed about 3,860 evacuees who had been living in temporary shelters since December to return home, according to Donato Sermeno III, director of the Office of Civil Defense–Negros Island Region.

The downgrade was based on several factors, including decreased volcanic gas emissions, improved ground deformation cycles, and the cessation of ash emissions after June 5, which began in October 2024.

Since June 5, volcanic activity at the crater has transitioned to quiet degassing, producing mostly steam-dominated plumes.

PHIVOLCS noted a short-term deflation of the volcano’s edifice from late June to early July, suggesting a pause in magma intrusion or depressurization due to reduced volcanic gas.

Since October 19, 2024, a total of 306 ash emission events and five explosive eruptions — between May 13 and June 3 — have been recorded at Kanlaon.

PHIVOLCS emphasized that while Alert Level 2 indicates decreased unrest, it does not rule out the possibility of sudden eruptions.

The agency warned of potential short-lived explosive events or steam-driven (phreatic) explosions that could produce pyroclastic density currents, ballistic projectiles, rockfalls, or lethal volcanic gases.

If monitoring data indicate renewed unrest, PHIVOLCS may raise the alert level back to Level 3.