The four barangays are located within the seven-kilometer extended radius of the permanent danger zone where the lava flow has been slowly advancing from the summit crater since July 15.
"Sometimes I just wake up in the middle of the night these past few days due to the heavy smell of sulfur," said Mabinit Barangay Captain Daniel Nuñez. Winds from the slopes of the 2,462-meter volcano carries the sulfur gas from the summit crater emits daily.
Nuñez estimates that the lava flow is about two kilometers from the barangay proper.
Nuñez, together with city councilor Celoy Chan, conferred with Cedric Daep, head of the provincial disaster management office.
"Evacuation order will be immediately implemented once the present alert level three is raised to four," Daep said.
He said he wants the 314 families or 1,394 residents to evacuate to the designated evacuation center at the San Roque Elementary School once the order is issued.
"Our problem here is not just the lava flow but the threat from pyroplastic flow to the permanent danger zone," he told The STAR.
Daep added that he has already coordinated with Mayor Noel Rosal to put up a marker delineating the boundary of the six-kilometer permanent danger zone.
Rosal has already prepositioned trucks for the evacuees of Mabinit (1,392 residents), Matanag (1,699), Buyuan (3,462) and Bonga (3,174) at pick-up points in Barangay halls or chapels.
Lava flow continues to flow at the volcano’s summit crater during the past 24 hours.
Sulfur gas emission rate was also very high at 12,548 tons per day, which indicates profuse degassing from the crater.
"It is more likely that Mayon will proceed to an explosion rather than just continue its lava extrusion activities because of very high SO2 emissions, which indicate massive degassing and the continuing push of magma towards the surface," Ed Laguerta, resident volcanologist of the Philippine Institute of Volcanology and Seismology (Phivolcs).
Ernesto Corpus, Phivolcs volcano monitoring chief, added that the possibility of a major eruption is very high with the sustained abnormal behavior of the volcano.
Phivolcs reported that some 388 tremors related to lava extrusion and falling volcanic debris were detected in the past 24 hours.
The Office of the Civil Defense in the Bicol region is closely monitoring the situation as aside from the threat of eruption, a tropical storm is also threatening the region. — With Cet Dematera, Shiela Crisostomo, Jaime Laude, James Mananghaya