Sporadic and weak lava fountaining, lava flow and degassing from the summit crater characterized Mayon’s activity yesterday. Two lava fountaining events yesterday produced 500 and 550 meter high ash plumes 10:38 AM and 1:52 PM both observed with rumbling sounds. The first event of these two events, lasting for an hour and fifty four minutes of sporadic lava flows, was accompanied by booming sounds audible within 10 kilometers of the summit crater. Throughout the night, quiet lava effusion fed lava flows in the Miisi and Bonga-Buyuan channels and barrancos between these with the exception of two weak lava fountaining events early this morning at 02:54 AM and 05:22 AM. These events were visually observed to have ejected high volumes of incandescent lava that have advanced to 3.2 kilometers and 4.5 kilometers, through the Miisi and Bonga-Buyuan channels respectively, from the summit crater.

A total of one hundred sixty four (164) volcanic earthquakes, most of which corresponded to sporadic and weak fountaining events, two (2) rockfall events and one (1) tremor event were recorded by Mayon's seismic monitoring network. Sulfur dioxide gas emission was measured at an average of 1,583 tonnes/day on 02 February 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.