Mayon’s condition for the past 24 hours was characterized by relative quiescence after a period of weak lava fountaining and lava effusion from the summit crater. Between 9:03 AM and 10:46 AM, two (2) discrete events of lava fountaining lasting four (4) to six (6) minutes generated steam-laden plumes that rose 800 meters from the summit before drifting west-southwest. In the evening, lava effusion from the vent was observed to continue feeding 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. One (1) lava-collapse event produced a pyroclastic density current (PDC) at 11:55 AM yesterday on Basud gully within 4 kilometers of the summit crater.

A total of fifty-one (51) volcanic earthquakes and sixteen (16) rockfall events were recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 2,787 tonnes/day on 26 February 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.

Alert Level 4 still 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.