Mayon shows slight increase in rockfalls, PDCs
Published Jul 22, 2023 06:09 am
The Philippine Institute of Volcanology and Seismology (Phivolcs) on Saturday, July 22, monitored a slight increase in rock falls and pyroclastic density currents (PDCs) in Mayon Volcano.Â
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)
In its bulletin, Phivolcs said Mayon Volcano Network recorded 175 rockfalls and four PDCs on July 22. The data is slightly higher than July 21's update, where 151 rockfalls and three PDCs were recorded. Meanwhile, slow effusion of lava flows from the crater with lengths of 2.8 kilometers (km) in Mi-is (south), 2.7 km in Bonga (southeastern), 600 meters (m) in Basud Gullies, and the four km lava collapse from the crater. Moreover, Phivolcs recorded 22 volcanic earthquakes, including a short-lived lava ejection with an ashing event that lasted 28 seconds. "Short-lived lava ejection that lasted 28 seconds accompanied by seismic and infrasound signals also occurred at 07:56 PM 21 July 2023," Philvocs said. Moreover, Mayon produced 1758 tonnes of sulfur dioxide flux and spewed a 500 m tall plume that drifted west-northwest and produced 1758 tonnes of sulfur dioxide flux.
Phivolcs noted that Mayon Volcano will remain on Alert Level 3 (intensified or magmatic unrest). Thus, Phivolcs still prohibited entry within a six-km radius Permanent Danger Zone (PDZ) and disallowed pilots of any aircraft from flying closer to the volcano. The prohibition is due to possible hazards that can occur, like rockfalls or landslides, or avalanches; ballistic fragments; lava flows, and lava fountaining; pyroclastic density currents; moderate-sized explosions; lahars during heavy and prolonged rainfall. *(*
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)
In its bulletin, Phivolcs said Mayon Volcano Network recorded 175 rockfalls and four PDCs on July 22. The data is slightly higher than July 21's update, where 151 rockfalls and three PDCs were recorded. Meanwhile, slow effusion of lava flows from the crater with lengths of 2.8 kilometers (km) in Mi-is (south), 2.7 km in Bonga (southeastern), 600 meters (m) in Basud Gullies, and the four km lava collapse from the crater. Moreover, Phivolcs recorded 22 volcanic earthquakes, including a short-lived lava ejection with an ashing event that lasted 28 seconds. "Short-lived lava ejection that lasted 28 seconds accompanied by seismic and infrasound signals also occurred at 07:56 PM 21 July 2023," Philvocs said. Moreover, Mayon produced 1758 tonnes of sulfur dioxide flux and spewed a 500 m tall plume that drifted west-northwest and produced 1758 tonnes of sulfur dioxide flux.
Remains in Alert Level 3
Phivolcs noted that Mayon Volcano will remain on Alert Level 3 (intensified or magmatic unrest). Thus, Phivolcs still prohibited entry within a six-km radius Permanent Danger Zone (PDZ) and disallowed pilots of any aircraft from flying closer to the volcano. The prohibition is due to possible hazards that can occur, like rockfalls or landslides, or avalanches; ballistic fragments; lava flows, and lava fountaining; pyroclastic density currents; moderate-sized explosions; lahars during heavy and prolonged rainfall. *(*
*Sonny Daanoy
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