Phivolcs downgrades Mayon alert status

LEGAZPI CITY --- Mount Mayon's abnormal activity has waned, prompting scientists to downgrade its status to Alert Level 1 (low level of unrest) from Level 2 (moderate level of unrest).

In its July 17 bulletin, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported the alert status of Mayon in Albay was downgraded due to the continued decline in its monitored parameters.

The lowering of the alert status of Mayon means the likelihood of an eruption occurring within the immediate future has weakened.

The Phivolcs bulletin said one of the parameters was the decline in volcanic earthquake activity observed in the past six months.

Seismic activity has declined to a daily average of one volcanic earthquake typically attributed to rock fracturing beneath the edifice and occasional rock fall.

The overall low-level seismicity signifies that there is no active magma intrusion at the volcano’s vent.

The sulfur gas (SO2) output has stabilized between 300 tons and 700 tons per day since January.

The low level of SO2 gas emission indicates a passive degassing or free of unwanted gas of stalled magma beneath the volcano edifice.

Steaming activity at the crater has ranged from weak to moderate.

Crater glow associated with superheated gas escaping the summit vent has been faint and only visible through the aid of a telescope.

The observation of stable lava dome, faint crater glow, and low gas emission since the beginning of the year signifies the cessation of magmatic activity.

Phivolcs reminded the public to avoid entry into the 6-km. Permanent Danger Zone (PDZ) due to perennial hazard of rock fall, avalanche, ash puff, and sudden steam-driven or phreatic eruption at the summit area.

“Furthermore, people living in valleys and active river channels are cautioned to remain vigilant against sediment-laden stream flows and lahars in the event of prolonged and heavy rainfall brought about by the advent of the rainy season,” the bulletin said. (PNA)