|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 03 March 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 minor degassing events, lava effusion and fountaining from the summit crater. A total of 68 degassing events between 3:09 PM and 10:02 PM generated 500 meter-tall grayish ash plumes that drifted southwest. Three (3) episodes of lava-collapse pyroclastic density currents (PDC) were visually observed between 9:39 AM and 3:10 PM yesterday on the Miisi and Basud Gullies within 4-5 kilometers of the summit crater. From 1:59 AM to 7:30 AM, sixteen (16) discrete episodes of lava fountaining lasting three (3) to twenty-three (23) minutes were seismically detected, accompanied by rumbling sounds audible beyond 10 kilometers of the summit. At night, lava flows were observed to continue moving downslope within 3.3 kilometers, 4.5 kilometers and 1.9 kilometers from the crater on the Miisi, Bonga and Basud Gullies, respectively.
A total of one hundred thirty-three (133) volcanic earthquakes and thirty (30) rockfall events were recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 1,403 tonnes/day on 02 March 2018. Deflation of the lower slopes that began on 20 February is still being recorded by electronic tilt. 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 last week.