Prospects of new explosive Mayon eruption down

Although Mayon Volcano is still considered to be in a "mild state of eruption," government volcanologists said yesterday the prospects of a sudden explosive eruption have diminished.

This, as the Philippine Institute of Volcanology and Seismology (Phivolcs) has observed a "gradual decline" in Mayon’s restiveness.

If this trend continues in the next few days, Phivolcs said it might lower the current alert level (five, the maximum).

The institute, in its latest bulletin, said Mayon’s seismic activity during the past 24-hour observation period was unremarkable, with the seismic network detecting only four rockfall-related, high-frequency harmonic tremors, 15 low-frequency volcanic quakes and nine low-frequency, short-duration harmonic tremors associated with shallow magma movement.

Mayon’s crater glow during the observation period was graded at Intensity two or fair, although Phivolcs said slight rains and clouds prevented clear and lengthy monitoring of the crater for any occurrence of lava sputtering or rumbling sounds.

The volcano, the institute said, remains slightly inflated but no intrusion of new magma has been detected and the sulfur dioxide emission was lower at 2,230 tons per day.

Although the prospects for an explosive eruption have diminished, Phivolcs cautioned against sudden small to moderate explosions that might still occur when voluminous hot materials get in contact with water.

Phivolcs warned that these explosions could trigger pyroclastic flows and rock avalanches within the danger zones.

Thus, it advised the public not to venture within the six-kilometer radius permanent danger zone and the seven-kilometer extended danger zone in the volcano’s southeast side.

The institute also asked residents along the banks of major river channels around Mayon to be extra vigilant during heavy rains to save themselves from life-threatening lahar flows.