Philippine Institute of Volcanology and Seismology, Powered by Joomla!
Mayon Volcano Bulletin 9 PDF Print
Tuesday, 22 December 2009 17:16

22 December 2009

7:00 AM

Mayon Volcano (13.2576 N, 123.6856 E) continued to show an intense level of activity during the past 24-hour observation period.  Seismic activity remained elevated in number and size as the seismic network detected a total of 1,266 volcanic earthquakes. Many of these volcanic earthquakes were recorded at maximum deflection and have continuously occurred since 12:21 PM, 20 December 2009.  Harmonic tremors were still continuously being recorded.

Sulfur Dioxide (SO2) emission rate remained very high and was measured at an average of 6,529 tons per day (t/d) yesterday. Visual observation was hampered by thick clouds covering the upper and middle slopes of the volcano since 6:00 AM yesterday.  However, an intensified crater glow was observed during a short cloud break last night. Audible booming and rumbling sounds were still intermittently heard for the past 24 hours.  Red hot lava also continuously flowed down along the Bonga-Buyuan, Miisi and Lidong gullies. The lava front has reached about 5 kilometers downslope from the summit along the Bonga-Buyuan gully.

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.