Lava continued to slowly come out of the summit crater of Mayon Volcano in Albay in the past 24 hours, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) said Saturday.
The slow effusion of lava “continued to feed and bulk up established lava flows on the Mi-isi (south), Basud (eastern), and Bonga (southeastern) gullies,” PHIVOLCS said in its bulletin.
The lava flow at Mi-isi gully remained at a length of 2.8 kilometers from the crater, while that at Basud gully was still at 600 meters from the crater.
At Bonga gully, the lava flow went further down to approximately 2.7 kilometers.
“Rockfall and pyroclastic density currents or PDCs generated by collapses of the lava flow margins as well as of the summit dome deposited debris still within four (4) kilometers of the crater,” PHIVOLCS said.
On Friday at 7:56 p.m., a short-lived lava ejection lasting 28 seconds was observed. This was accompanied by seismic and infrasound signals.
PHIVOLCS said 22 low frequency volcanic earthquakes including one short-lived lava ejection with an ashing event were recorded.
There were also four pyroclastic density current (PDC) and 175 rockfall events recorded by the Mayon Volcano Network.
Meanwhile, an average of 1,758 tonnes of volcanic sulfur dioxide was emitted by the volcano on Friday.
PHIVOLCS noted a deflation of the eastern lower flanks of the volcano in early July and inflation of the northwest middle flanks in the third week of July.
The volcano remains generally inflated, it added.
“Alert Level 3 is maintained over Mayon Volcano, which means that it is currently in a relatively high level of unrest and hazardous eruption within weeks or even days could still be possible,” PHIVOLCS said.
The agency recommended that the six-kilometer radius Permanent Danger Zone remain evacuated. This area is threatened by possible PDCs, lava flows, rockfalls, and other volcanic hazards, it added.
PHIVOLCS also said pyroclastic density currents, lahars, and sediment-laden streamflows along channels draining the edifice may occur.
“Heavy rainfall could generate channel-confined lahars and sediment-laden streamflows in channels where PDC deposits were emplaced,” it added.
PHIVOLCS again reminded that flying close to the volcano’s summit is dangerous as ash from sudden eruption may be hazardous to aircraft.
Ash fall events may most likely occur on the volcano’s south side, PHIVOLCS said, basing it on prevailing wind pattern. —KG, GMA Integrated News