The Philippine Institute of Volcanology and Seismology on Sunday raised Mayon Volcano’s status alert from Level 1 (abnormal) to alert Level 2 (increased unrest.)
Phivolcs said it was prompted to raise the alert level after Mayon generated a steam-driven (phreatic) eruption on Saturday afternoon. This volcanic activity propelled grayish steam and ash plumes as high as 2,500 meters, which drifted to the southwest.
“This means that current unrest is probably of magmatic origin, which could lead to more phreatic eruptions or eventually to hazardous magmatic eruptions,” the institute warned.
Seismic records show that the activity started around 4:21 p.m. on Saturday. It lasted for about an hour and 47 minutes. A faint crater glow was observed at 10:16 p.m. of Saturday.
“Since the eruption, rockfall events have been intermittently recorded and are continuing as of the time of the release of this bulletin,” Phivolcs said.
In its latest bulletin, the institute also reported that traces of ash fell on the following areas in Bicol: Barangay Anoling, Daraga, Barangays Sua, Quirangay, Tumpa, Ilawod and Salugan of Camalig and in Barangays Tandarora, Maninila and Travesia in Guinobatan.
It added that residents of Camalig town proper reported sulfuric odor while residents of Barangays Anoling and Daraga heard rumbling sounds.
Due to this, the public is warned of further eruptions and is asked to desist from entering the six-kilometer Permanent Danger Zone around the volcano to minimize risks from sudden explosions, rockfall, and landslides.
Phivolcs said residents should remain vigilant of ash fall. It added that these ash fall events may most likely affect communities on the western and southwestern flanks downwind of Mayon’s crater since these may likely occur on the southwest side of the volcano.
“People should cover their nose and mouth with damp, clean cloth or dust mask,” the institute advised.
Meanwhile, civil aviation authorities advised pilots “to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft.”
Since October and November 2017, Mayon’s edifice had inflationary changes or a slight swelling as indicated by ground deformation data recorded by continuous GPS and tilt. -PhilSta-