|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 24 February 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.
SUMMARY | Alert Level 4 remains in effect over Mayon Volcano.
Mayon’s activity in the past 24 hours was characterized by generally quiet lava effusion and degassing from the summit crater. During daytime yesterday, between 10:32 AM and 1:44 PM, six (6) episodes of lava-collapse pyroclastic density currents (PDC) were visually observed on the Miisi, Basud and Bonga-Buyuan Gullies within 4-5 kilometers of the summit crater. At night, lava effusion from the vent continued to feed lava flows that have maintained fronts at 3.3 kilometers, 4.5 kilometers and 900 meters on the Miisi, Bonga and Basud Gullies, respectively, from the summit crater.
A total of three (3) volcanic earthquakes and eight (8) rockfall events were recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 2070 tonnes/day on 23 February 2018. Deflation of the lower slopes that began on 20 February was recorded by electronic tilt, consistent with the transition to quiet lava efffusion at the summit crater. Nonetheless, overall electronic tilt and continuous GPS data indicate that the edifice is still swollen or inflated relative to November and October 2017, consistent with campaign Precise Leveling data acquired this week.