Mayon Volcano Bulletin

12 August 2006

8:00 AM

Six (6) explosions occurred at Mayon Volcano (13.2576°N, 123.6856°E) for the past 24-hour observation period. The seismic network recorded these mild outbursts at 5:14AM, 5:18AM, 12:11PM, 2:25PM, and 3:50PM, yesterday and 3:54AM today. A grayish cloud was briefly seen after the 3:50PM ash explosion, which quickly dissipated and drifted to the east-southeast of the volcano. The 3:50PM ash explosion was among the largest to date, based on instrumental records since the volcano began spewing ash last 07 August 2006. The smaller ash explosions of yesterday and early morning today were not observed due to thick rain clouds which covered the summit and middle slopes of the volcano.

A high level of seismicity prevailed. Forty-eight (48) volcanic quakes signified magma ascent. Lava fragments, which detached from the summit and lava flow deposits generated about 442 tremor episodes. The Sulfur Dioxide (SO₂) emission also remained high, at 6,876 tonnes per day (t/d) yesterday.

The public is reminded that Alert Level 4 is still in effect, which means that a high probability of hazardous explosive eruption exists. The eight (8) kilometers EXTENDED DANGER ZONE (EDZ) in the southeast sector of the volcano should be observed at all times. In connection with this, PHIVOLCS reminds everyone to observe safety precautions relevant with this alert level. At other areas around the volcano, this EDZ is seven (7) kilometers from the summit crater. Areas outside of the EDZ are advised to be on the alert for updates regarding their status for possible evacuation in case volcanic activity intensifies.