MANILA, Philippines — State volcanologists on Friday observed an increase in activity in Mayon Volcano’s crater, causing ashfall in parts of Tabaco City.
According to Phivolcs, four dome-collapse pyroclastic density currents or PDCs from the volcano’s summit lava dome have been increase activity Mayon volcano recorded.
“A series of four (4) dome-collapse pyroclastic density currents or PDCs from Mayon volcano’s summit lava dome has been recorded since 6:09 PM this evening, 30 June 2023,” Phivolcs said in its advisory.
PDC refers to mixtures of fragmented volcanic particles, hot gases, and ash that rush down the volcanic slopes or rapidly outward from a source vent at high speeds.
The series of PDCs flowed for around four minutes down the Basud Gully within a distance of 3-4 kilometers from the crater.
Before that, a longer, four-minute-long PDC on the Basud Gully was recorded earlier in the day at 1:01 pm.
“Ashfall from the PDCs has been reported by residents of Tabaco City,” Phivolcs said.
State seismologists also recorded a total of 48 weak low-frequency volcanic earthquakes from Mayon volcano since 5:00 am on Friday.
The volcano monitor also noted an increase in sulfur dioxide emission (SO2) since Thursday, while SO2 emission measured on Friday averaged 1,002 metric tons/day.
Mayon Volcano has been under Alert Level 3 since June 8, with the unrest seen to last for a few months based on the volcano monitor’s observations.