At approximately 7:47 PM of 11 June 2023, lava flow activity from the summit crater of Mayon Volcano commenced. The activity formed two lobes of lava that emplaced within 500 meters from the crater and shed lava debris on the Mi-Isi (south) and Bonga (southeastern), and Basud (eastern) Gullies that fell within 2 kilometers from the crater. This development was accompanied by only weak seismic activity and a slight swelling of the upper portions of the edifice prior to lava flow based on electronic tilt data. Within the past 24-hour period, the Mayon Volcano Network recorded twenty-one (21) weak volcanic earthquakes and two hundred sixty (260) rockfall events. Three (3) dome-collapse pyroclastic density currents (PDC) that lasted two (2) to four (4) minutes were also detected. Sulfur dioxide (SO2) emission averaged 642 tonnes/day on 11 June 2023. Short-term observations from EDM and electronic tiltmeter monitoring show the upper slopes to be inflating since February 2023. Longer-term ground deformation parameters based on EDM, precise leveling, continuous GPS, and electronic tilt monitoring indicate that Mayon is still inflated, especially on the northwest and southeast.

Alert Level 3 is raised over Mayon Volcano, which means that it is currently in a relatively high level of unrest as magma is at the crater and hazardous eruption is possible within weeks or even days. 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. Heavy rainfall could generate channel-confined lahars and sediment-laden streamflows in channels where PDC deposits were emplaced. 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.

DOST-PHIVOLCS