|This serves as a notice for the lowering of Mayon Volcano’s status from Alert Level 4 (hazardous eruption imminent) to Alert Level 3 (decreased tendency towards hazardous eruption).|
PHIVOLCS: MAYON VOLCANO BULLETIN 11 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 degassing, weak lava fountaining and lava flow from the summit crater. Twelve (12) obscured lava fountaining events between 12:35 PM and 9:48 PM yesterday lasting four (4) to twenty (20) minutes were seismically recorded. Degassing events generated white to gray ash plumes that rose 300 to 2500 meters above the summit before drifting southwest. These events were accompanied by rumbling sounds audible within 10 kilometers of the summit crater. At night, lava flows were observed to continue moving downslope within 3.3 kilometers, 4.5 kilometers and 1.9 kilometers from the crater on the Miisi, Bonga and Basud Gullies, respectively.
A total of one hundred eighty-six (186) volcanic earthquakes and seventeen (17) rockfall events were recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 2,060 tonnes/day on 08 March 2018. Deflation of the lower flanks that began on 20 February is still being recorded by electronic tilt, although a period of slight inflation of has been recorded by Precise Levelling (PL) surveys this past week. Overall ground deformation data indicate that the edifice is still swollen or inflated relative to pre-eruption baselines.