Philippines: Mayon volcano update 08 Mar 2000

The Mayon Volcano seismic network recorded low frequency volcanic quakes and short duration harmonic tremors. The measured SO2 gas emission rate of 3,900 tonnes/day, although low compared to recent measurements, is still way above the volcano's baseline level. Likewise, ground deformation surveys showed that the volcano's edifice is slightly inflated. At night, when the volcano's summit area was visible, intense crater glow continue to be observed. These data and observations suggest that the volcano is still at a state of unrest following the 01 March 2000 ash ejections.
Alert Level 5 remains hoisted over Mayon Volcano. Entry into the 6-km Permanent Danger Zone and the extended 8-km danger zone in the southeast quadrant is still strictly prohibited. The airspace to the west and southwest of the volcano are now generally clear of airborne ash. Some hot lahar flows may occur due to the presence of pyroclastic deposits on the volcano's slopes which, may be eroded and remobilized during intense and prolonged rainfall. Potential sites for lahar flows include the Mabinit and Buyuan-Padang river channels in Legaspi City; Miisi and Anoling channels in Daraga; Tumpa channel in Camalig; Maninila and Upper Nabonton channels in Guinobatan; Basud-Lidong channel in Sto. Domingo, Bulawan channel in Malilipot; San Vicente and Buang channels in Tabaco and Upper Nasisi in Ligao. Authorities are advised to monitor the condition of major roads crossing these channels and in particular those channels radiating southeast of Mayon. People residing near river banks as well as in low-lying areas are reminded to be always on the alert as these sites are most susceptible to potentially destructive and life-threatening flows. Temporary evacuation may be necessary in case of sustained and intense rainfall in the abovementioned areas.