LEGAZPI CITY (1June2013/PNA) – The Philippine Institute of Volcanology and Seismology (Phivolcs) on late Friday afternoon raised Mount Mayon volcano’s alert status from level 0 (normal) to level one (abnormal) due to the presence of fumes and visible crater glow and as a precaution to the public that the volcano is exhibiting extraordinary behavior.
This, despite the fact that most monitoring parameters remain within baseline levels, according to Governor Joey Salceda, Albay provincial Disaster Risk Reduction and Management Council (PDRRMC) chair.
The Phivolcs raised the alert level after the volcano exhibited abnormalities indicated by bluish steam emission and persistent but weak crater glow, Salceda said Saturday.
The raising of the volcano’s alert level prompted the PDRRMC to issue on Friday an advisory strictly prohibiting any “human activity” inside the six-kilometer permanent danger zone (PDZ) at the slopes of the volcano.
As a counter disaster control measure, Salceda directed local disaster councils, various village chiefs and police and military authorities to enforce the “no human activity” inside the designated PDZ –including mountain climbing, farming, orchids gathering and ATV (all terrain vehicle) tour activities.
He also directed the disaster councils of the cities of Legazpi, Ligao and Tabaco and the towns of Daraga, Camalig, Sto. Domingo, Malilipot and Guinobatan to be on alert and to closely monitor advisories released by the Phivolcs and PDRRMC.
Ed Laguerta, Phivolcs resident volcanologist, said that aside from the steam emission and crater glow, the agency instruments noted slight ground inflation.
Laguerta explained that these slight bulging and crater glow may be an indication that magmatic activity is increasing in the volcano’s vent.
A Phivolcs bulletin for the past 36-hour observation period after the phreatic explosion on May 7 said Mt. Mayon continue to emit weak and short-lived bluish fumes with persistent crater glow of Intensity 1 (weak).
It said the persistent weak glow may denote heating of the atmosphere above the crater due to a steady emission of magmatic gas.
Laguerta, however, dispelled fears that the abnormalities are no indication yet of an imminent eruption as other parameters are not yet present.
He clarified that aside from the crater glow, steam emission and ground deformation shown by Mayon volcano, other parameters would include low- and high-frequency volcanic quakes, high sulphur dioxide emission, lava fountaining, lava flows, magmatic activities, pyroclastic flows, and steam and ash explosions.
On May 7, the 2,600-meter high Mount Mayon volcano had a phreatic (steam-driven) explosion, spewing a three-kilometer high ash cloud.
The explosion killed four German mountaineers and a local guide when rocks fell on them while scaling the volcano.
A week after the incident, a lone Russian mountaineer made an unauthorized climb on the volcano but accidentally fell, broke his right ankle and got trapped at the volcano’s Miisi gulley in Daraga town at the southwest quadrant of the mountain.
PDRRMC data indicated that Mount Mayon’s latest recorded eruption was in December 2009 where 8,637 families or 40,991 persons living in 30 villages along the volcano’s foot were evacuated.
The Phivolcs reiterated that the six-km PDZ is a no-entry zone to the public because of the perennial danger of life-threatening rockfalls, avalanches, ash puffs and sudden phreatic or steam-driven eruptions. (PNA)