LEGAZPI CITY, Albay: The Philippine Institute of Volcanology and Seismology (Phivolcs) on Friday said Mayon Volcano’s eruption will produce about 30 to 40 million cubic meters of volcanic materials.
Dr. Winchell Ian Sevilla, Phivolcs supervising science research specialist, discovered a 4.21 millimeters inflation in the volcano’s edifice within Barangay Buang in Tabaco City a few days ago. On Friday, another swelling measuring 1.1 millimeters was detected in Lidong village in Sto. Domingo town, bringing to 17 millimeters the swelling recored since Phivolcs raised Mayon’s status to alert level 3 on September 15.
Sevilla said that for two weeks, the volcano’s edifice is rapidly bulging due to fresh magma build up which is now within the 500 meter elevation from the foot of the volcano.
“The current situation of Mayon Volcano is very critical because the crater is clogged up with molten rocks while fresh magma beneath the volcano is ascending which means too much pressure. This is the reason why the edifice is swelling overtime to accommodate the increasing magma,” Sevilla explained.
The latest ground deformation leveling survey conducted by Phivolcs showed that Mayon’s surface in the Sto. Domingo side had further inflated by 1.1 millimeters.
Though this swelling is smaller than the 4.21 mil-limeters measured at the Buang precise leveling instrument in Tabaco City, the figures mean that Mayon’s surface inflation is sustained.
“This means that Mayon’s surface inflation continues despite the drop of its gas emission. While the fighting of forces between the magma pressure and the weight of the lava dome continues, we will remain in a wait-and-see mode,” Sevilla said.
Phivolcs on Friday detected at least three volcanic earthquakes and a rockfall event, while the sulfur dioxide (SO2) emission further dived to 299 tons, lower than 387 tons the other day.
Sevilla reiterated its warning of a big eruption should the magma and gas build up continue before Mayon would finally explode.
He said that the recent surface inflation may indicate that the magma moving inside Mayon could reach as much as 40 million cubic meters.