|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 07 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 brief periods of weak lava fountaining, gravity-driven lava flow and subsequent quiescence. Two (2) episodes of weak lava fountaining at 08:28 AM and 02:40 PM lasted for two (2) hours and consisted of fifteen (15) and six (6) discrete events, respectively. These events generated dark gray ash plumes that rose 100 to 300 meters above the summit crater before drifting southwest and were accompanied by rumbling sounds audible beyond 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 seventy-six (76) volcanic earthquakes and thirteen (13) rockfall events were recorded by Mayon's seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 4,459 tonnes/day on 06 March 2018. Deflation of the lower slopes that began on 20 February is still being recorded by electronic tilt and by Precise Levelling (PL) surveys. Nonetheless, overall ground deformation data indicate that the edifice is still swollen or inflated relative to pre-eruption baselines.