PHIVOLCS: Inflation of flanks observed in Mayon

Inflation of the northwest middle flanks has been observed in Mayon Volcano this July, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) said Friday.

"Longer-term ground deformation parameters from EDM, precise leveling, continuous GPS, and electronic tilt monitoring indicate that Mayon is still generally inflated relative to baseline levels," said PHIVOLCS in its latest bulletin.

Parts of Mayon, meanwhile, were seen deflating, according to PHIVOLCS.

“Short-term observations from electronic tilt and GPS monitoring indicate a deflation of the eastern lower flanks in early July 2023 and inflation of the northwest middle flanks in the third week of July 2023,” it said.

The lava flow from the crater along Bonga gully extended from 2.4 kilometers to 2.5 kilometers on Friday, according to PHIVOLCS.

“Alert Level 3 is maintained over Mayon Volcano, which means that it is currently in a relatively high level of unrest as magma is at the crater and hazardous eruption within weeks or even days is possible,” PHIVOLCS said.

A total of 83 volcanic earthquakes, 151 rockfall events, and three pyroclastic density current events had been recorded in the volcano in the past 24 hours.

The volcano emitted 1,581 tonnes of sulfur dioxide on Thursday.

A moderate emission of plumes was also observed from the volcano, reaching up to 1,000 meters, drifting to the southwest and west-southwest directions.

A total of 33 ashing events occurred in the volcano on Wednesday and Thursday.

Slow effusion of lava flows from the crater were still observed along Mi-isi gully extending up to 2.8 kilometers and along Basud gully up to 600 meters.

A lava collapse 4 kilometers from the crater was also observed.

PHIVOLCS warned that heavy and prolonged rainfall could generate channel-confined lahars and sediment-laden streamflows in channels where PDC deposits are emplaced.

“Increased vigilance against pyroclastic density currents, lahars, and sediment-laden streamflows along channels draining the edifice is also advised,” PHIVOLCS said.

It added that pilots should avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft.

Alert Level 3 in Mayon Volcano was raised on June 8 after three PDC events were observed on the Bonga (southeast) and Basud (east) gullies of the volcano.

A total of 38,375 people or 9,867 families in 26 barangays in Bicol have been affected by Mayon's activity, the National Disaster Risk Reduction and Management Council (NDRRMC) on Friday.

Of the total number, 18,782 individuals or 5,372 families are staying in 27 evacuation centers, while 1,431 individuals or 409 families are taking shelter in other places.

A total of 1,120 livestock animals were also preemptively evacuated.

A state of calamity was declared in 18 cities and municipalities due to the volcano’s activity.

Assistance worth P240,947,631 has been provided to the victims. —Joviland Rita/ VAL, GMA Integrated News