|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 25 January 2018 8:000 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.
Between 06:02 AM yesterday to 03:00 AM this morning, six (6) episodes of intense but sporadic lava fountaining from the summit crater lasting nine (9) minutes to fifty-eight (58) minutes occurred. The lava fountains reached 400 meters to 500 meters high and generated ash plumes that reached 3 kilometers to 5 kilometers above the crater. The events fed lava flows on the Mi-isi and Bonga Gullies, sprayed near-vent lava spatter, and fed incandescent rockfall on the summit area. Pyroclastic density currents or PDCs on gullies heading the Mi-isi, Lidong/Basud, and Buyuan Channels were also observed. The runout of PDCs on the Buyuan Channel is now exceeding 5 kilometers from the summit crater.
A total of thirteen (13) tremor events, six (6) of which correspond to the lava fountaining events, two (2) episodes of pyroclastic density current or PDC generation from lava collapse, and numerous 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 Mi-isi Gully and by shedding from the summit dome onto the Bonga Gully. Currently, the Mi-isi and Buyuan lava flows have advanced to three (3) kilometers and one (1) kilometer, respectively, from the summit crater.