PHIVOLCS: MAYON VOLCANO BULLETIN 22 March 2018 8:00 A.M.SUMMARY | Alert Level 3 currently prevails over Mayon Volcano.
Mayon’s activity in the past 24 hours was characterized by general quiescence, degassing from the summit crater and gravity-driven lava flow. Weak emissions of white steam-laden plumes drifting southwest and east-southeast occurred throughout the day. Lava flows could be observed at night to be moving downslope on the Miisi, Bonga and Basud Gullies within 3.3 kilometers, 4.5 kilometers and 1.9 kilometers of the crater, respectively. A total of twenty four (24) rockfall events were recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 545 tonnes/day on 21 March 2018. Slight inflation of the lower slopes that began on 11 March is still being recorded by electronic tiltmeter, consistent with results of Precise Leveling (PL) surveys on 10 - 19 March 2018. Overall ground deformation data indicate that the edifice is still swollen or inflated relative to pre-eruption baselines.