The lava flow from Mayon Volcano reached about one kilometer down its south and southeast gullies during the previous 24-hour monitoring of the active volcano in Albay, according to the Philippine Institute of Volcanology and Seismology (Phivolcs) on Tuesday morning, June 13.

“Very slow effusion of lava from the summit crater emplaced lava flow and collapse debris on the Mi-isi and Bonga gullies within approximately a kilometer from the crater,” Phivolcs said in its bulletin issued at 8 a.m.

It also detected one dome collapse pyroclastic density current (PDC) that lasted two minutes.

In the past 24 hours, Mayon Volcano had one volcanic earthquake and 221 rockfall events, based on Phivolcs’ seismic and visual observations. 

Thin ash from rockfalls was observed, as well as continuous moderate degassing from the summit crater, which produced steam-laden plumes that bent and crept downslope before drifting northeast.

“Fair crater glow or ‘banaag’ and incandescent rockfall shed from new fluidal lava at the summit of Mayon Volcano was observed,” Phivolcs said.

Mayon Volcano spews ash and lava as seen from Legazpi City, Albay on June 11, 2023. The province of Albay was placed under state of calamity due to the threat of volcanic eruption. (ALI VICOY/MANILA BULLETIN)

Alert level 3 stays

As there is magma at the crater, Mayon Volcano’s status was raised to alert level 3 on June 8, which means it is “currently in a relatively high level of unrest.”

Phivolcs warned that “hazardous eruption is possible within weeks or even days.”

The evacuation of residents within the six-kilometer permanent danger zone has been recommended due to risk of pyroclastic density currents (PDCs), lava flows, rockfalls, and other volcanic hazards.

Phivolcs warned the public to be cautious of PDCs, lahars, and sediment-laden stream flows along channels draining the volcano edifice.

It pointed out that heavy rainfall could cause channel-confined lahars and sediment-laden stream flows in channels where PDC deposits were emplaced.

Likewise, it said that ash fall events may “most likely” occur on the south side of the volcano, based on the current prevailing wind pattern.

Phivolcs advised civil aviation authorities to ask pilots to avoid flying close to the volcano because ash from sudden eruption may pose hazards to aircraft.