DOST-PHIVOLCS Mayon’s activity in the past 24 hours was characterized by sporadic and weak lava fountaining, lava flow and degassing from the summit crater. Six (6) discrete lava fountaining episodes that lasted ten (10) to twenty-three (23) minutes were recorded by the seismic network. These generated dirty white to brownish ash plumes that rose to two hundred fifty (250) meters above the summit crater before drifting southwest. Three (3) episodes of lava collapse pyroclastic density current (PDC) events were visually observed yesterday between 5:57 AM and 9:16 AM in the Basud and Bonga-Buyuan Gullies. Lava flow sustained at 3.3 kilometers, 4.5 kilometers and 900 meters on the Miisi, Bonga and Basud Gullies, respectively, from the summit crater. Pyroclastic density currents or PDCs remained confined within the farthest recorded reaches of 4.6, 4.5 and 4.2 kilometers on the Miisi, Bonga and Basud Gullies, respectively.

A total of fifty-four (54) volcanic earthquakes, most of which corresponded to lava fountaining events, and one (1) rockfall event was recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission averaged 1,339 tonnes/day on 17 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.

Alert Level 4 remains 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. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft. DOST-PHIVOLCS maintains close monitoring of Mayon Volcano and any new development will be communicated to all concerned stakeholders.