|Mayon Volcano Bulletin 6|
|Sunday, 20 December 2009 10:13|
20 December 2009
Mayon Volcano (13.2576 N, 123.6856 E) continues to exhibit a high level of activity for the past observation period. A total of two hundred twenty two (222) volcanic quakes and tremors was recorded by the seismic network. One (1) of these events was an explosion type earthquake that produced a dirty white to grayish ash column that reached a maximum height of about 500m above the summit before drifting southwest. Harmonic tremors were continuously recorded by the seismic instruments.
During a cloud break this morning, steaming activity ranged from dirty white to light brown in color. Night observation still showed intensified crater glow and continuous rolling down of incandescent materials from the crater.
The advancing lava flow has now reached approximately 4.5 kilometers downslope from the crater along Bonga-Buyuan Gully. Sulfur Dioxide (SO2) emission increased from 2,034 tonnes per day (t/d) to 7,024 t/d.
Alert Level 3 remains hoisted over Mayon Volcano. The persistently high volcanic unrest indicates that the possibility of a hazardous volcanic eruption is high. Thus, PHIVOLCS-DOST recommends that the 6-km radius Permanent Danger Zone (PDZ) around the volcano and the 7-km Extended Danger Zone (EDZ) on the southeast flank of the volcano should be free from human activity because of sudden explosions that may generate hazardous volcanic flows. In addition, areas in the south that are outside the 7 kilometer danger zone but within 8 kilometers of the crater should be extra alert for increased volcanic activity. Active river channels and those perennially identified as lahar prone in the southern sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall. PHIVOLCS–DOST is closely monitoring Mayon Volcano’s activity and any new significant development will be immediately posted to all concerned.