Philippines

Mayon Volcano Bulletin 2 Apr 2000

Format
Situation Report
Source
Posted
Originally published
0700H

During the past observation period, a still high level of seismicity prevailed over Mayon Volcano as forty (40) low frequency and three (3) high frequency volcanic earthquakes and four (4) episodes of high frequency tremors were recorded by the Mayon Volcano telemetered seismic network. Sulfur Dioxide emission rate increased from 3,600 tonnes per day (t/d) yesterday to 6,210 t/d. During cloud breaks, a moderate to weak emission of white steam was noted drifting towards west-southwest. A faint glow at the crater continued to be observed in the evening.

The still elevated low frequency volcanic earthquakes is expected due to the continued degassing process of residual magma that is considered part of post eruptive activity. This also correlates to increase in the rate of steam outputs and the continued occurrence of glow at the tip of the cone.

PHIVOLCS maintains Alert Level 2 over Mayon Volcano, which means that the probability of hazardous explosive eruption is now minimal. However, the public is reminded to strictly follow the six (6) kilometer radius Permanent Danger Zone. The seven (7) kilometer Extended Danger Zone in the southeast portion of the volcano remains in effect since the eruptive deposits in the vicinity of Bonga gully are still unstable and are expected to be eroded especially during intense and prolonged rainfall on the mountain slopes. Hence, secondary pyroclastic flows, rockfalls and ash fallout can occur any time. The areas of highest potential danger includes the lowlands fronting the Mabinit and Buyoan-Padang river channels in Legaspi City; Miisi in Daraga; Tumpa, Anoling and Quirangay channels in Camalig; Maninila channel in Ginobatan; Basud-Lidong channel in Sto. Domingo; Bulawan channel in Malilipot; San Vicente and Buang in Tabaco and upper Nasisi and upper Nabonton in Ligao.