LEGAZPI CITY -- Volcanologists here predicted yesterday a major eruption of Mayon Volcano in Albay if the present "discharge rate" of the lava pile increases about five times, from the present 0.7 to 2 cubic meters per second.
This developed as a crater glow was observed for about five minutes past midnight yesterday, indicating that magma or hot molten rock is nearing the volcano's summit, volcanologists said.
The magma, which has a temperature ranging from 2,000 to 2,500 degrees Celsius, cast a bright orange glow observed via a fixed telescope.
"If the crater glow, along with the lava trickle and ground deformation, intensifies in the coming days, we will raise the alert level (from three) to four," said volcanologist Alex Baloloy.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said the continuous magma buildup was accompanied by moderate steaming, slight inflation of the southeast slopes, a triple increase in sulfur dioxide emission and volcanic tremors.
Volcanologist Ed Laguerta said the present discharge rate of the lava pile might only result in lava overflow. Mayon's crater is about 200 meters in diameter.
The volume of the crater dome is estimated at half a million cubic meters.
"The eruption might be as explosive as that in 1984 if the discharge rate of the lava pile reaches 10 cubic meters per second," he said.
With such speed of lava ejection, he said there would be less degassing which could result in a major eruption.
Laguerta, however, warned that a mere lava overflow is also dangerous because the pyroclastic flow puts lives and property at risk.
Cedrip Daep, chief of the provincial disaster management office, said every contingency measure is now in place in anticipation of an eruption.
Daep said villagers from all five barangays situated within the six-kilometer radius permanent danger zone around Mayon have been evacuated.