The Philippine Institute of Volcanology and Seismology has lowered the alert status of Mount Mayon to Level 3, but warned that the volcano remains restive.
A Phivolcs advisory issued today (Tuesday, March 6) said the lowering of the alert status from Level 4 (which means hazardous eruption is imminent) to Level 3 (decreased tendency towards hazardous eruption) was due to the continued decline in volcanic activity.
Phivolcs volcanologist, Dr Ed Laguerta, said yesterday that Mayon’s activity had declined, as shown by reduced intensity and frequency of events, suggesting a gradual depletion of magma at the shallow levels of the volcano.
Activity has diminished to sporadic degassing with associated ash plumes, weak lava fountaining, quiet lava flow and lava collapse.
Dr Laguerta said there were low frequency events associated with degassing at the summit and signals of rockfall and small volume of pyroclastic density currents generated by the collapsing front and margins of lava flows on the Miisi, Bonga and Basud gullies.
In the past 24 hours, only four volcanic earthquakes and 44 rockfall events were recorded by the seismic monitoring network, he said.
He added that in terms of gas emission, sulphur dioxide emissions had varied from a maximum of 4,270 tons per day to 1,400 on March 3.
Dr Laguerta also said that the volcano is expected to remain active and that in the event of uptrend or pronounced change in the monitoring parameters, the alert status may be returned to Level 4.
On the other hand, if there is a noticeable and persistent downtrend in the monitoring parameters, then the alert status may be lowered to Level 2.
The public is still warned to avoid entering the six-kilometre permanent danger zone due to hazards of rockfall, avalanche, ash puff and sudden steam-driven eruptions.
In a report released by the Albay Public Safety Emergency Management Office today, there are 2,666 families or 10,836 individuals still in evacuation centres.
Most affected by Mayon have been Tabaco City with 569 evacuated families; Daraga (337 families); Camalig (378 families); Malilipot (1,303 families) and Guinobatan (79 families).