MANILA, Philippines — State volcanologists detected a sudden increased seismic activity and ground deformation at Mayon Volcano yesterday afternoon, prompting them to advise residents within the seven to eight-kilometer radius to be ready for evacuation.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said the increased seismicity was accompanied by a noticeably sharp jump in ground tilt on the west sector of the edifice, which started on June 25.
“A sudden change in monitoring parameters has been detected and is being closely monitored,” Phivolcs said.
Earlier, 102 mild quakes were recorded around the volcano from 5 a.m. to 3 p.m., indicating that magma continued to ascend to the summit crater.
The earthquakes were accompanied by eight dome-collapse pyroclastic density currents that lasted three minutes, and 263 rockfall events.
Paul Alanis, Phivolcs resident volcanologist at the Lignon Hill Observatory in this city, said the 102 quakes had low energy and could not trigger strong explosions.
“These detected earthquakes still lack energy to trigger a strong explosion. But of course we are closely watching Mayon to determine what could take place next,” Alanis said.
He said the quakes were not as strong compared to the ones recorded in 2018 days before the volcano erupted.
“We are also observing other parameters to determine where Mayon’s abnormal condition will proceed, including the sulfur dioxide emission,” Alanis said.
Lava flows remain at 1,300 meters and 1,200 meters along Mi-isi and Bonga gullies, respectively, from the summit crater, while collapse debris were still at 3,300 meters from the 250-meter-wide crater.
Phivolcs also recorded 925 tons of sulfur dioxide and plume emissions that rose 100 meters high.
“Despite these increases in the values of the abnormal signs, Mayon remains within Alert Level 3,” Alanis said.
Phivolcs said heavy rain could generate channel-confined lahars and sediment-laden stream flows.
Pilots have been advised to avoid flying close to the volcano’s summit as ash generated by any sudden eruption can be hazardous to aircraft.
“Based on the current prevailing wind pattern, ashfall events may most likely occur on the south side of the volcano,” Phivolcs said.
Meanwhile, the number of families displaced by the increased activity of Mayon has reached 10,642 families or 41,483 individuals.
Of the number, 5,354 families or 18,706 people are staying in 28 evacuation centers.
The government said it has spent more than P101.1 million in assistance for the evacuees. — Cet Dematera, Michael Punongbayan, Rudy Santos