Mayon Volcano Bulletin

06 August 2006

9:00 AM

A brief overflight of Mayon (13.2576°N, 123.6856°E) this morning has shown that lavas discharged from the summit crater are also spilling into the Bonga gully, east of the Mabinit channel. Consequently, the supply of lava to Mabinit channel has decreased. The Mabinit lava flow deposit will therefore further slow down its progress at present conditions and probably stop a short distance beyond the 6 kilometer-radius Permanent Danger Zone boundary. The lava front in this part is a little more than 6.1 aerial kilometers from the crater at 269 meters elevation. The lava front slowly descending in the general direction of Bonga is presently located about 5.1 aerial kilometers from the crater and at 320 meters elevation.

Some lavas blocks discharged from the  summit are also falling into gullies facing Miisi and Buyoan and the general wide spread of material falling from the crater shows the broad impact zone spanning the whole southeast sector of the volcano.

A tally of seismic activity showed 371 tremor episodes caused by lavas impacting the slopes. Twelve (12) volcanic earthquakes were detected, and this signifies magma ascent within Mayon.

The Sulfur Dioxide (SO₂) emission rate for yesterday amounted to 1,919 tonnes per day (t/d).

Alert Level 3 is in effect, which means that the six (6) kilometer-radius Permanent Danger Zone (PDZ) should be off-limits. As the Mabinit lava deposit slowly descends beyond the PDZ boundary in the Southeast, PHIVOLCS reminds everyone to keep a safe distance because sudden collapse of the front and sides of the flow may produce some pyroclastic avalanches, which could impact areas well beyond the lava flow’s footprint. Although the lava flow is moving slowly, it has entered vegetated areas and has produced some small fires as trees and shrubs are consumed. PHIVOLCS therefore reminds the public to be also aware of potential spread of fire in the upper reaches of Mabinit and Bonga. Residents of Barangays within the 8 kilometers in the Southeast sector of the volcano, particularly in the towns of Daraga and Sto. Domingo and in Legaspi City, are therefore advised to be alert and to be prepared for evacuation if activity escalates.