Philippines

Mayon Volcano Bulletin 29 Jun 2001

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Other
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Posted
Originally published
8:00 A.M.

During the past twenty four hours, Mayon's telemetered seismic network detected ten (10) high frequency short duration harmonic tremors and six (6) low frequency volcanic earthquakes. These lower counts compared to yesterday were due to the smaller amplitude volcanic earthquakes being obscured by the higher amplitude water torrent signals. Sulfur Dioxide emission rate was at 1,674 tonnes/day which is still much above the normal value of 500 tonnes/day. Ground deformation measurements employing EDM and electronic tiltmeters indicate the volcano's edifice remains inflated.

Crater glow was observed to be at Intensity II (fair) and lava continues to trickle from the summit crater. Other observations were small rockfalls, vigorous steaming of the hot lava deposits and muddy stream flows along major river channels.

The status of Mayon Volcano remains at Alert Level 5. Based on the volcano monitoring parameters and visual observations, explosive eruptions are still possible in the following days. PHIVOLCS reminds the public to keep away from the six (6) kilometers Permanent Danger Zone and eight (8) kilometer Extended Danger Zone in the Southeast portion of the volcano since the eruptive deposits in the vicinity of Bonga gully remain unstable and are expected to be eroded. Secondary pyroclastic flows, rockfalls and ash fallout can occur any time due to unstable volcanic materials deposited on steep grounds. If heavy rains occur over the volcano, the public should avoid going near river channels around Mayon because of potential lahar flows.

PHIVOLCS