|Mayon Volcano Bulletin 11|
|Thursday, 24 December 2009 20:00|
Mayon Volcano’s (13.2576 N, 123.6856 E) intense level of unrest persisted during the past 24-hour observation period. Seismic activity remained elevated in number and size as the seismic network detected 815 volcanic earthquakes and recorded tremors up to 4:14pm yesterday. Many of the volcanic earthquakes were recorded at maximum deflection. Twenty one (21) ash explosions were recorded during times of good visibility, with the ash columns reaching heights of up to 1.5 km. above the summit. Lava fountaining, reaching a maximum height of 500 meters, was observed at 11:12 PM, 11:14 PM, 11:20 PM and 11:32 PM.
One hundred twenty four (124) audible booming and rumbling sounds were intermittently heard for the past 24 hours. Red hot lava also continuously flowed down along the Bonga-Buyuan, Miisi and Lidong gullies. Measurement of Sulfur Dioxide (SO2) emission rate yielded a value of 5, 737 tonnes/day.
Alert Level 4 remains hoisted over Mayon Volcano, meaning a hazardous eruption is possible within days. Thus, PHIVOLCS-DOST reiterates that the Extended Danger Zone (EDZ) from the summit of 8-km on the southern sector of the volcano and 7-km on the northern sector should be free from human activity. Areas just outside of this EDZ should prepare for evacuation in the event hazardous explosive eruptions intensify. 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.