LEGAZPI CITY (27-Nov-2012/PNA) – The Philippine Institute of Volcanology and Seismology (Phivolcs)lowered on Tuesday from Alert Level 1 (abnormal) to normal level the condition of Mayon Volcano.
Ed Laguerta Phivolcs resident volcanologist said the agency decided to declare the state of the volcano to normal after Mayon volcano ceased to exhibit abnormal seismicity such as crater glow, ground deformation, volcanic quakes and sulphur dioxide emission.
The volcano’s normal status means that no explosive eruption is foreseen in the immediate future.
Laguerta in an interview said Mayon’s Alert Level 1 status had been raised for two years since March 2010 because of the sustained abnormalities it manifested.
Recently Mayon Volcano exhibited a general decline of monitoring parameters to normal value, indicating a return to normalcy.
Phivolcs seismic instruments have not recorded for the past weeks occurrences of earthquakes and volcanic tremors associated with magmatic activity.
Ground deformation monitoring using Precise Leveling (PL) surveys on the northern and eastern flanks, combined with recently emerging patterns in ground tilt monitoring, indicate that minimal ground deformation recorded in Mayon may not be associated with new magmatic intrusion.
Gas emission from the crater was way below the 500 tonnes a day normal level, while steaming is often weak and occasionally wispy, Laguerta said.
Crater glow has also ceased since March 2012, indicating diminished superheated gas from shallow magma at the vent.
Laguerta said despite the normalcy of Mount Mayon, he warned the public not to enter the 6-km Permanent Danger Zone or PDZ due to perennial hazards of rockfalls, avalanche, ash puffs and steam-driven explosions 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 rain falls.
Mayon Volcano exhibited seismic abnormalities on July 2009 and had its full blown eruption on December 16, 2009, where it displaced some 10,032 families or 47,563 people, said Maria Cristina Ador, Albay Provincial Disaster Risk Reduction and Management Council (PDRRMC) statistician.
She said the eruption affected the towns of Daraga, Camalig, Guinobatan, and Sto Domingo including the cities of Legazpi, Ligao and Tabaco.
Damages wrought by the volcanic eruption was placed at P16.6 million in agriculture and infrastructures. (PNA)