The lava effusion from Mayon Volcano is still occurring slowly, feeding and enlarging existing lava flows along three gullies that run down the volcano’s slopes, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Sunday, July 23.
In the last 24 hours, Phivolcs said lava flows on the Mi-isi and Basud gullies on Mayon’s southern and eastern flanks have maintained distal lengths of approximately 2.8 kilometers (km) and 600 meters, respectively.
Meanwhile, the lava flow on Bonga gully on the southeastern flank of Mayon Volcano grew from 2.7 kilometers on July 22 to 2.8 kilometers on July 23.
Phivolcs also noted that debris was still deposited within four kilometers of the crater from rockfall and pyroclastic density currents (PDCs) caused by the collapses of the lava flow margins and the summit dome.
“In total, five LFVQs (low-frequency volcanic quakes), four PDCs, and 158 rockfall events were recorded by the Mayon Volcano Network,” it said.
Mayon Volcano ejects massive pyroclastic density currents (PDC) toward the Basud Gully in Sto. Domingo town in Albay province around 5:30 p.m. on July 10, 2023. (Niño Luces/Manila Bulletin)
Alert level 3 still up
Given these observations, Phivolcs said Mayon Volcano remains on Alert Level 3, which means it is still in a relatively high level of unrest and that a potentially hazardous eruption may occur within weeks or even days.
Communities near the restive volcano are recommended to maintain increased vigilance against lahars and sediment-laden stream flows along channels draining the volcano edifice, as heavy rainfall could cause channel-confined lahars and sediment-laden stream flows.
READ: https://mb.com.ph/2023/7/20/phivolcs-warns-of-lahar-flow-near-mayon-volcano-due-to-td-egay-s-rains
Since Mayon Volcano’s status was upgraded twice in the past month, first to level 2 on June 5 and then to level 3 on June 8, Phivolcs strongly advised that entry into the six-kilometer permanent danger zone be strictly prohibited.
Furthermore, it warned that ash fall may occur in areas south of Mayon Volcano due to current wind patterns.
Phivolcs advised pilots to avoid flying near the volcano’s summit because ash from a sudden eruption can be dangerous to aircraft.