26 December 2009

7:00 AM

Mayon Volcano (13.2576 N, 123.6856 E) continued to exhibit a high level of activity during the past 24-hour observation period. Thirty three (33) ash explosions with dirty white to brownish ash columns that reached maximum heights of 1,000 m above the summit were observed during times of good visibility. Twenty six (26) rumbling and two (2) hissing sounds from the volcano were heard at the Lignon Hill Observatory in Legaspi City. Seismic activity remained elevated as the seismic network recorded a total of four hundred six (406) volcanic earthquakes. One hundred forty two (142) rock fall events related to detachment of lava fragments at the volcano’s upper slopes were also detected. Flowing red hot lava and rolling incandescent lava fragments were continuously observed at Bonga, Padang and Miisi gullies. Sulfur Dioxide (SO2) emission rate remained high and was measured at an average of 8,993 tonnes per day (t/d) yesterday.

Alert Level 4 is 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.