At 11:51 AM yesterday, one (1) lava-collapse fed pyroclastic density current or PDC event on Miisi Gully occurred that produced a 1250 meter-high ash cloud that drifted southwest. This was succeeded by two (2) more PDC events on the Basud Gully that lasted until 12:09 PM and produced ash clouds that drifted southwest. Low whitish to light-gray plumes were continuously emitted from the crater throughout the day, and sporadic ashing began at 5:11 PM. This was followed by continuous and sluggish lava effusion in the evening and early morning that continually fed lava flows on the Miisi and Bonga Gullies. Intermittent short-lived lava fountaining to 200m heights occurred throughout the night.

A total of two hundred ninety-eight (298) volcanic earthquakes, four (4) distinct episodes of PDC generation from lava collapse, and fifty-two (52) rockfall events were recorded by Mayon's seismic monitoring network. Rockfall events were generated by the collapsing lava front and margins of the advancing lava flows on the Bonga and Miisi Gullies. Sulfur dioxide gas emission was measured at an average of 3,428 tonnes/day on 30 January 2018. Electronic tilt and continuous GPS measurements indicate a 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.