Philippines, Mayon Volcanic Activity

On 05 June 2023, the alert status of Mayon Volcano was raised to Alert Level 2 (Increasing Unrest) following a sharp increase in the incidence of rockfall from its summit lava dome from an average of 5 events per day in May 2023 to 49 events per day on 5 June 2023.

Pronounced increases in rockfall signify the extrusion of new lava beneath the summit lava dome, destabilizing this and causing its spalling or collapse. Rockfall activity increased while volcanic earthquake activity was absent to sparse, sulfur dioxide emissions were at background or baseline levels and short-term ground deformation consisted mainly of swelling of the middle to upper slopes of the edifice Days of increased incidence and volume of rockfall based on seismic records were followed by the generation of short pyroclastic density currents (PDCs) or “uson” in the morning of 08 June 2023. The PDCs were emplaced on the Bonga (Legaspi City), Miisi (Daraga) and Basud (Sto. Domingo) Gullies as far as two (2) kilometers from the summit crater. This indicated that new, less degassed lava was already being spalled from the summit dome and that eruption of very slowly extruding magma had slightly increased.

On 08 June 2023, 12:00 PM, Alert Level 3 (Increased Tendency Towards Hazardous Eruption) was raised. In the evening thereof, incandescent rockfall generated by intermittent collapse of an apparent fluidal lava portion of the summit dome were deposited on the above gullies within a kilometer of the crater. In the early morning on 10 June 2023, a new summit dome impinging a remnant on the southeast crater floor was observed.

As of 10 June 2023, 7:00 PM, a total of 654 rockfall events and 7 PDCs have been recorded by the Mayon Volcano Network since 01 June 2023. Average sulfur dioxide flux increased beyond baseline levels to 1,205 tonnes/day. All other monitoring parameters remain unchanged. Fair crater glow or “banaag” and incandescent rockfall shed from new fluidal lava at the summit of Mayon Volcano was observed in the night of 10 June 2023.

As of 11 June 2023, 8:00 AM, Mayon Volcano is at Alert Level 3 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.