|PUBLIC ADVISORY: Notice of raising Mayon Volcano’s status from Alert Level 3 to Alert Level 4 as of January 22, 2018.|
PHIVOLCS: MAYON VOLCANO BULLETIN 30 January 2018 8:00 A.M.PHIVOLCS has raised the alert level to Alert Level 4 in effect over Mayon Volcano. The public is strongly advised to be vigilant and desist from entering the eight (8) kilometer-radius danger zone, and to be additionally vigilant against pyroclastic density currents, lahars and sediment-laden stream flows along channels draining the edifice.
Beginning 7:50 last night, energetic lava effusion with sporadic lava fountaining events and generation of lava-collapse fed pyroclastic density currents or PDCs or “uson” occurred until 11:06 PM. Although the upper slopes were heavily obscured, the seismic record indicated onset of this eruption cycle with a large-volume lava collapse at 7:50 PM at the summit crater that fed PDCs on the Miisi and Bonga Gullies, followed by lava fountaining at 8:16 that lasted 8 minutes. This was followed by obscured large-volume lava effusion that lasted for an hour and 36 minutes, interspersed with sporadic lava fountaining and/ or PDC generation based on the seismic record. Sporadic lava fountaining was visually and seismically detected and persisted until 11:06 PM. The lava fountains reached 200 meters high and generated ash plumes that reached 1.5 kilometers above the crater. Significant ashfall was reported in Camalig and Guinobatan, Albay before 9:00 PM, possible due to the lava fountaining and PDC events.
A total of one hundred nineteen (119) volcanic earthquakes, nine (9) tremor events, two (2) of which correspond to lava fountaining events, two (2) distinct episodes of PDC generation from lava collapse, and sixty-eight (68) rockfall events were recorded by Mayon's seismic monitoring network. Rockfall events were generated by the collapsing lava front and margins of the advancing lava flow on the Bonga and Miisi Gullies. Sulfur dioxide gas emission was measured at an average of 1,916 tonnes/day on 25 January 2018. Electronic tilt and continuous GPS measurements indicate a sustained swelling or inflation of the edifice since November and October 2017, consistent with pressurization by magmatic intrusion.