|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 10 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 near continuous lava fountaining, lava flow and degassing from the summit crater. Sixty-six (66) successive lava fountaining episodes since 08:08 AM last February 9, 2018 have been recorded by the seismic network. Discrete episodes lasted three (3) to forty-six (46) minutes and were accompanied by rumbling sounds audible beyond 10 kilometers of the summit crater. Incandescent lava fountains 200 meters tall generated steam-laden plumes that rose up to 800 meters from the summit before drifting northeast. Throughout the night, lava flows and consequent incandescent rockfalls were observed in the Miisi and Bonga-Buyuan channels. Effused volumes of incandescent lava flows have advanced to 3.3 kilometers, 4.5 kilometers and 900 meters down the Miisi, Bonga and Basud Gullies, respectively, from the summit crater. Pyroclastic density currents or PDCs have deposited to the 4.6, 4.5 and 4.2 kilometer reaches of the Miisi, Bonga and Basud Gullies, respectively.
A total of seventy-six (76) volcanic earthquakes, most of which corresponded to lava fountaining events were recorded by Mayon's seismic monitoring network. Sulfur dioxide gas emission was measured at an average of 336 tonnes/day on 09 February 2018. Electronic tilt and continuous GPS still record sustained swelling or inflation of the edifice since November and October 2017, consistent with pressurization by magmatic intrusion.