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SINCE the Alert Level status was raised from Alert Level 1 to Alert Level 2 on 05 June 2023, repeated collapse of the growing summit dome of Mayon Volcano has generated an increasing number and volume of rockfall events.
This means that Mayon is exhibiting magmatic eruption of a summit lava dome, with increased chances of lava flows and hazardous PDCs affecting the upper to middle slopes of the volcano and of potential explosive activity within weeks or even days.
A total of 267 rockfall events and 2 volcanic earthquakes were recorded from 05 to 08 June, compared to 54 rockfall events from 01 to 04 June 2023.
These events had durations of one to three minutes and transported lava debris within a kilometer range of the southern upper slopes.
The volume of discrete rockfall events increased on 3 June based on the seismic record, signaling an increase in the rate of dome growth. Three pyroclastic density current or PDC events on the Bonga (southeast) and Basud (east) Gullies were observed today at 6:18 AM, 9:53 AM and 11:00 AM.
The PDCs lasted four to five minutes based on the seismic record and emplaced within a kilometer of the summit crater. In contrast, SO2 emission remains at baseline or background levels.
Short-term ground deformation data from continuous GPS, electronic tilt, and EDM monitoring indicate persistent inflation of the southeastern middle and upper slopes since February 2023.
The overall monitoring parameters indicate that very slow extrusion of shallow degassed magma is ongoing and is incrementally increasing in rate; i.e., effusive magmatic eruption is taking place.
It is therefore recommended that the 6-km radius Permanent Danger Zone (PDZ) be evacuated due to the danger of PDCs, lava flows, rockfalls and other volcanic hazards. Increased vigilance against pyroclastic density currents, lahars and sediment-laden streamflows along channels draining the edifice is also advised. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft. Based on the current prevailing wind pattern, ash fall events may most likely occur on the south side of the volcano. DOST-PHIVOLCS maintains close monitoring of Mayon Volcano and any new development will be communicated to all concerned stakeholders.
