Philippines: Mayon volcano update 05 Mar 2000

Originally published
As of the 5th of March, as reported to SVE by PHILVOLCS, that since its latest major explosions on 1 March, Mayon volcano in the Philippines has gradually calmed down, and on 4 March only minor volumes of lava were still extruded. However, it cannot be excluded that further explosive activity will occur - as has happened during all recent eruptions of the volcano - and between 60,000 and 80,000 people are still living in evacuation centres.
At present the volcano has apparently entered a phase of lava emission with sporadic episodes of minor ash puffs. Ash and steam emission from both the summit crater and new lava flow deposits produced a haze over the southwestern sector, particularly in the municipalities of Camalig, Guinobatan and Ligao. Visual scanning of the summit was hampered because of thick cloud cover during the entire observation period.

SO2 flux measurement yielded a value of 14,500 tons/day. Ash clouds derived from the new lava flow deposits apparently produced a significant portion of this emission rate. Ground deformation measurements indicate the volcano has slightly deflated during this quiet period, following the 01 March 2000 ash ejections.

Alert Level 5 remains in effect over Mayon Volcano. The danger zones are still defined at the 6 kilometer-radius around the volcano and at the 8 kilometer-radius in the southeast sector. These danger zones should remain evacuated at all times. Areas to the west and southwest of the volcano are still expected to experience some ashfall because of continuous degassing at the summit crater and from new lava and pyroclastic deposits. Due to rainfall and to the presence of pyroclastic deposits, lahar flows may occur along major tributaries draining from Mayon Volcano. Local officials are reminded to take the necessary precautions and possible temporary evacuation of these areas should there be renewed explosive eruption. Residents near river banks and low-lying areas are therefore reminded to be very alert against these potentially destructive and life-threatening flows during rains.