Mayon Volcano Bulletin

11 August 2006

8:00 AM

Two (2) mild explosions were recorded by the Mayon seismic network at 11:13AM and 3:21 PM yesterday  There were no visual observations of explosive and other activity because thick rain clouds covered the summit crater and the middle slopes of the volcano throughout the day. Twenty-seven (27) volcanic earthquakes and 368 tremor episodes were also detected during  the past 24 hours. These volcanic earthquakes still indicate ascent of magma from inside the volcano while the tremor episodes were generated by collapsing lava blocks and lava fragments of the advancing lava flows upslope and facing Mabinit and Bonga.

The Sulfur Dioxide (SO₂) emission rate of the volcanic plume was still high, measured at 7,068 tonnes per day (t/d) yesterday compared with previous 6,573 t/d. The above manifestations of the volcano reflect its continuing high unrest.

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 this connection, 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