The alert level on Albay’s Mayon Volcano has been raised from 1 to 2 – meaning an “increasing level of unrest” – following an aerial survey yesterday that showed a significant increase in the summit dome from the previous 40,000 cubic meters to 48,000 cubic meters.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said ocular inspection of the summit confirmed the presence of freshly extruded lava at the base of the lava dome.
“The event (growing dome) was signaled only by observations of thin remobilized light-colored ash, likely derived from lava fragmentation during the extrusion process, on the floor of the Miisi Gully since Oct. 2, 2022,” Phivolcs said.
In contrast, Phivolcs explained “short-term ground deformation data relative to August 2022 yielded short-term deflation on the eastern to southeastern Mayon edifice, and only slight, short-term inflation on the general western to southwestern flanks.”
Phivolcs also said that longer-term ground deformation parameters based on EDM (electronic distance meter), Precise Leveling, continuous GPS and electronic tilt monitoring show that Mayon has been slightly inflated, especially on the northwest and southeast, since 2020.
“Lastly, sulfur dioxide emission last measured by campaign Flyspec on Oct. 1, 2022 averaged 391 tons per day, below baseline level,” the state agency added.
Phivolcs said that as observed, there is current unrest driven by shallow magmatic processes that could eventually lead to phreatic eruptions or even precede hazardous magmatic eruption.
It advised the public to be vigilant and desist from entering the six-kilometer radius Permanent Danger Zone to minimize risks from sudden explosions, rockfall and landslides.
Cedric Daep, chief of the Albay Public Safety and Emergency Management Office, said his office is reviewing contingency plans in case of a “volcanic eruption scenario.”
“We are now reviewing our existing warning system, communication protocol, evacuation procedure and transportation needs,” Daep told The STAR.