NAGA CITY, Camarines Sur: Mayon Volcano does not share a common chamber or canal for magma or molten rocks with other Bicol volcanoes that can trigger them to similarly erupt, a retired American geologist said on Tuesday.
“There is no such link except that they are part of the 260-kilometer long Bicol volcanic arc, and no, the eruption of Mayon will not cause them to erupt as well,” said Chris Newhall, a retired volcanologist of the US Geological Survey as he allayed fears and popular belief that the current activity of Mayon will generate a chain reaction among the region’s volcanoes.
He told participants of the 2nd Fr. Frank Lynch, SJ. Lecture Series at the Ateneo de Naga University that unlike earthquakes, volcanoes show tell-tale signs of their impending eruption, like changes in surrounding vegetation or in animal behavior.
At 10 p.m. on Monday, Mayon had a “lava fountaining,” spraying jets of lava into the air in rapid formation.
The Philippine Institute of Volcanology and Seismology (Phivolcs) raised Alert Level 3 and said
on Tuesday morning there were nine tremors, three other short-duration “lava fountaining,” and 75 lava collapse events in the last 24 hours.
“Level 4 is possible anytime soon once we observe certain signs such as an explosive eruption or lava ‘fountaining,’ which can be seven-kilometers high,” Phivolcs chief Renato Solidum said.|
More than 25,000 people were evacuated from 25 villages in the towns and cities of Camalig, Guinobatan, Ligao, Daraga, Tabaco and Malilipot.
“Collapse events and some degassing events at the summit crater generated ash that rose to two kilometers and fell on villages of Camalig, Guinobatan and Polangui,” Phivolcs said.
It advised the public to desist from entering the six-kilometer permanent danger zone and the seven-kilometer extended danger zone on the southern flanks because of danger of rockfalls, landslides and sudden explosions. |
Newhall, who is married to a Bicolana and who studied volcanoes in the US, Guatemala, Indonesia, Ecuador, the Democratic Republic of Congo and Japan, related the histories of three other Bicol volcanoes, Bulusan in Sorsogon and Isarog and Iriga in Camarines Sur.
Mount Bulusan, he said, is a quaint case as it is but a small volcano in an otherwise large one, the Irosin volcano, whose eruption 41,000 years ago may have been much more extensive and explosive than the 1814 or 1897 eruption of Mayon, but which is now just a large caldera of its old self.
Newhall aded that the Isarog and Iriga mountains are also active volcanoes based on their eruptive behavior in the past 10,000 years.
He clarified that the recorded 1642 eruption of Mount Parker in South Cotabato was wrongly ascribed to Mount Iriga, which he said had erupted at a much earlier time, a thousand years before the coming of the Spaniards.
Isarog, on the other hand, had histories of eruptions 25,000 years ago as evidenced by the debris deposits in Tinambac town, another one which occurred some 5,300 to 5,600 years ago, and in 1914-1916.
“When they will erupt again, we cannot tell. Maybe not even in our lifetime, but certainly the Philippine Institute of Volcanology will know with the help of modern monitoring equipment, as they did with the Pinatubo,” said Newhall, who now lives in Santo Domingo, Albay with his wife, Glenda.
The lecture series is named after the late Jesuit anthropologist whose study on the “sadit” and “dakulang tawo” in Canaman town placed it and the region in the academic map of the country.
WITH GLEE JALEA