Mayon: A calmer volcano. TED ALJIBE/Agence France-Presse
LEGAZPI CITY — Mount Mayon on Friday was placed under Alert Level 1 (low level of unrest) from Level 2 (moderate level of unrest).
The Philippine Institute of Volcanology and Seismology (Phivolcs) said the downgrade was due to the continued decline in its monitored parameters.
The declaration means the likelihood of an eruption occurring within the immediate future has weakened. There was a decline in volcanic earthquake activity observed in the past six months.
Seismic activity has also declined to a daily average of one volcanic earthquake typically attributed to rock fracturing beneath the edifice and occasional rockfall.
The overall low-level seismicity signifies that there is no active magma intrusion at the volcano’s vent.
The sulfur gas output has stabilized between 300 tons and 700 tons per day since January.
The low level of SO2 gas emission indicates a passive degassing (free of unwanted gas of stalled magma) beneath the volcano’s 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.
The public is still reminded to avoid entry into the 6-km Permanent Danger Zone due to perennial hazard of rockfall, avalanche, ash puff, and sudden steam-driven or phreatic eruption at the summit area.