Mayon Volcano logs fast-moving hot ash flow after lava collapse — PHIVOLCS

A lava-collapse pyroclastic density current (PDC) was observed at Mayon Volcano on Wednesday morning, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).

In an update, PHIVOLCS said: “At the moment: Ongoing lava-collapse pyroclastic density current at Mayon Volcano. Details to follow.”

PHIVOLCS later said in a message to reporters: “Lava Effusion with collapse PDC started at 11:22 am with plume height of 4000m [Above Mean Sea Level] drifting southwest. Ended at 11:37 a.m.,”

Mayon Volcano remained under Alert Level 3, or intensified unrest, on Wednesday.

In the past 24 hours, PHIVOLCS said lava flows extended up to 3.8 kilometers along the Basud Gully, 3.2 kilometers along the Bonga Gully, and 1.6 kilometers along the Mi-isi Gully.

PHIVOLCS also observed episodic minor Strombolian activity and short-lived lava fountaining from the summit crater.

The agency recorded 35 volcanic earthquakes, including 26 volcanic tremors lasting between seven and 84 minutes.

It also logged 350 rockfall events and seven pyroclastic density current signals.

A moderate plume rising 1,250 meters above the crater drifted west-northwest, west-southwest, and southwest.

Sulfur dioxide emissions averaged 1,295 tonnes per day on Tuesday.

Ground deformation data indicated short-term deflation of the volcanic edifice, although shorter-term inflation was observed on the northeastern flank.

PHIVOLCS reiterated that entry into the six-kilometer permanent danger zone remains prohibited due to continuing threats such as rockfalls, landslides, ballistic fragments, lava flows, pyroclastic density currents, and moderate-sized explosions.

The agency also warned aircraft against flying close to the volcano.

Residents living near river channels and low-lying areas were likewise advised to remain alert for possible lahars during periods of heavy and prolonged rainfall.—MCG, GMA News