Mayon Volcano Update

07 August 2006

5:00 PM

A total of six (6) ash explosion events occurred at Mayon Volcano (13.2576°N, 123.6856°E) starting from 7:08AM to 7:48AM. The explosions sent ash and steam up to 800 meters above the summit.

The front of the slowly advancing lava flow along the Mabinit channel has reached some 200 meters downslope of the six (6) kilometer radius Permanent Danger Zone (PDZ) boundary, at elevation 262 meters above sea level. A second lava flow is slowly descending in the Bonga gully and is presently located about 5.4 aerial kilometers from the crater, at 305 meters elevation.

The lava fragments tumbling onto the upper and middle southeast slopes facing Miisi, Mabinit, Bonga and Buyoan generated some 462 tremor episodes. From inside the volcano, 21 earthquakes occurred and these indicated magma ascent. In addition, the seismic network recorded six explosion-type earthquakes which accompanied these ash explosions.

The Sulfur Dioxide (SO₂) emission rate for today amounted to 12,745 tonnes per day (t/d).  The very high flux is due to arrival of fresh, gas-rich magma to the crater.  Explosive eruptions are therefore very probable.

Alert Level 4 is in effect, which means that a hazardous explosive eruption is imminent within the coming days. To prevent undue harm to the public, an EXTENDED DANGER ZONE (EDZ), defined as an area within eight (8) kilometers from the summit crater located in the southern sector, is now recommended.

PHIVOLCS reiterates evacuation of the following localities included in the EDZ:

1. Barangays Anoling and downstream areas including Tinuburan, Sua, Upper Quirangay, Salugan, and Upper Cabangan of Camalig Municipality,

2. Barangays Miisi and areas to its south including Budiao, Matnog and Baņadero of Daraga Municipality; Mabinit, Bonga, Matanag, Upper Padang and Buyoan of Legazpi City.

At other portions around Mayon, the following areas, within seven (7) kilometers of the crater, should be evacuated:

3. Barangay  Baligang of Ligao,

4. Barangays Bonot, Magapo, Oson, Part of Buhian and Comon of Tabaco City,

5. Barangays Canaway, Calbayog, and part of San Roque of Malilipot Municipality,

6. Barangays Lidong, Fidel Surtida, San Isidro, Sta. Misericordia and San Antonio of Sto. Domingo.

Residents of Barangays outside the 8 kilometers EDZ in the Southeast sector of the volcano are advised to prepare for evacuation if activity escalates. Notice on further evacuation is under continuing evaluation and recommendations shall be issued at the appropriate time.