AERIAL view of Mayon last month MARC ALVIC ESPLANA/INQUIRER SOUTHERN LUZON
LEGAZPI CITY, Philippines—The Philippine Institute of Volcanology and Seismology (Phivolcs) warned the public about the dangers posed by the huge lava dome, or pile of lava, that had formed at the crater of Mayon Volcano even if there is no big eruption.
Paul Karson Alanis, science research specialist of Phivolcs, said that once the lava dome collapses, it would cause a huge pyroclastic flow, a mixture of lava fragments, rocks and volcanic gases that would flow through the channels of the volcano.
He said a geodetic survey on Wednesday showed that the lava dome had a volume of 855,000 cubic meters, which is equivalent to more than 85,000 truckloads of rocks, that could explode should there be an eruption.
Alanis said the pyroclastic flow could be triggered by a quake, “probably magnitude 5.”
He said pyroclastic materials have a temperature of 600 degrees Celsius or enough heat to kill people.
“This is very hot, as we see this lava dome glowing at night. You need 100 degrees Celsius to boil water, so it means pyroclastic materials are six times hotter,” he explained.
Phivolcs’ Thursday bulletin recorded one rock fall event while the sulfur dioxide emission increased to 606 tons per day compared to 569 tons per day on Wednesday.
Alanis said the lava dome was considered “unstable.”
He said Mayon was currently in a “quiet eruption” mode, which means magma is slowly moving out of the crater.
“The volcano is emitting magma little by little,” Alanis said.
There had been a lull after quakes and rock fall events decreased, but eruption is still imminent, he added.
He reiterated that the alert level of Mayon, currently 3, couldn’t be lowered.
“If we look at our tilt level meter, Mayon has inflated because of the pressure inside, or if we compare it to humans, if we have wounds, our skin would be swollen,” he said.
Earlier, Cedric Daep, head of Albay Public Safety and Emergency Management Office, said the lava dome was tilted to the southeastern side of Mayon, so areas on this side would be exposed to pyroclastic or even lava flow.
These areas, which are in the 6- to 8-kilometer radius extended danger zone, cover 32 barangays in Legazpi City and the municipalities of Camalig, Daraga and Sto. Domingo.
In Sto. Domingo, Albay, hundreds of evacuees started to build temporary houses through “bayanihan.” The houses are made of wood and anahaw leaves.
Alicia Balleta, 74, said life was tough in the shelters but neighbors were still all too willing to help.
Xandro Valenzuela, 40, said they had no supply of water while food was seldom distributed by the local government.