Manila Bulletin
Philippines
National
Mayon's collapsing lava dome, lava front trigger more pyroclastic density currents
Philippines
National
Mayon's collapsing lava dome, lava front trigger more pyroclastic density currents
Mayon's collapsing lava dome, lava front trigger more pyroclastic density currents
Published Jul 7, 2023 04:52 am
The Philippine Institute of Volcanology and Seismology (Phivolcs) has recorded more pyroclastic density currents (PDCs) in Mayon in the last 24 hours as a result of the collapse of the volcano's lava dome and lava front.
In a bulletin released on Friday, July 7, Phivolcs said the Mayon Volcano Network had recorded seven dome collapse pyroclastic density currents (PDC), which lasted five seconds to three minutes and 29 seconds, and eight lava front collapse PDC, which generated a 500-meter-high light brown plume.
Moreover, there have been 216 rockfalls and an ongoing "repetitive pulse tremor" since 3:47 p.m. on July 3.
Phivolcs said PDCs are mixtures of fragmented volcanic particles or pyroclastics, hot gases, and ash that rush down the volcanic slopes or rapidly outward from a source vent at high speeds.
It noted that the “very slow” effusion of lava from Mayon Volcano has continued to feed lava flows and collapse debris on the Mi-isi, Bonga, and Basud gullies on the southern, southeastern, and eastern flanks of the volcano, respectively.
Lava flows have progressed by about 2,800 meters and 1,300 meters, respectively, along the Mi-isi and Bonga gullies, while collapsed debris has advanced by 4,000 meters along the Basud Gully.
Phivolcs also pointed out that the Mayon Volcano continues to emit a “moderate” amount of sulfur dioxide, producing 600-meter-high steam-laden plumes that drifted west-southwest and west-northwest.
PHOTO CAPTION: This image from the Mayon Volcano Observatory captures the volcano's "intense glare, active degassing, and effusion" from its summit crater on June 29, 2023. (Phivolcs)
PHOTO CAPTION: This image from the Mayon Volcano Observatory captures the volcano's "intense glare, active degassing, and effusion" from its summit crater on June 29, 2023. (Phivolcs)
Hazardous volcano eruption still possible
According to Phivolcs, Mayon Volcano’s current activity still shows an “increased tendency toward hazardous eruption,” and as such, Alert Level 3 is maintained. There is still the possibility of a “hazardous eruption within weeks or even days” because of the presence of magma at the crater, Phivolcs said. Mayon Volcano’s status has been upgraded twice in the past month, first to level 2 on June 5 and then to level 3 on June 8 due to increasing unrest. Phivolcs strongly advised the evacuation within the six-kilometer permanent danger zone due to PDCs, lava, rockfalls, and other volcanic hazards.. In addition, Phivolcs advised communities to maintain increased vigilance against PDCs, 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. Pilots were also asked to avoid flying close to the volcano because ash from a sudden eruption may pose hazards to aircraft. According to Phivolcs, communities on the southern side of Mayon Volcano may most likely experience ash fall events based on the current wind pattern.