Philippines

Mayon Volcano Bulletin 1 Apr 2000

Format
Situation Report
Source
Posted
Originally published
0700H

Thirty-six (36) low frequency and two (2) high frequency volcanic earthquakes and three (3) episodes of high frequency short duration harmonic tremors were detected by Mayon Volcano telemetered seismic network during the past 24 hours. Ground deformation and Sulfur Dioxide emission rate measurements were not carried out due to inclement weather condition prevailing over the volcano area. During cloud breaks, a moderate emission of white steam was noted drifting towards west-southwest. A faint glow at the crater continued to be observed in the evening.

The persistent occurrence of low frequency earthquakes and short duration harmonic tremors and high level of Sulfur Dioxide emission rate are associated with degassing of residual magma. This degassing process is considered part of post-eruptive activity of the volcano. The presence of still-hot magma near the summit caused the crater to glow at night.

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) kilometers radius Permanent Danger Zone. The seven (7) kilometers 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. Thus, 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.