Advancing lava threatens 7,500 Albay residents

LEGAZPI CITY — Mayon’s continuous lava flows in the past two weeks now pose a serious threat to nearly 7,500 residents of 10 barangays inside the volcano’s six-kilometer radius permanent danger zone.

This, after a team from the Philippine Institute of Volcanology and Seismology (Phivolcs) conducted field observation in Barangay Mabinit here and warned local officials that the lava mass has advanced by about 300 meters from the volcano’s crater.

"If the flow rate persists, the lava flow is expected to reach the boundary of the six-kilometer radius permanent danger zone in two to three days," Phivolcs said in a bulletin.

In fact, volcanologists said the Bonga gully, the major lava channel at the southeast flank, is already filled with about six million to 10 million cubic meters of volcanic debris.

Ed Laguerta, Phivolcs’ resident volcanologist, said pyroclastic flows when Mayon erupts could create new channels since the existing ones are heavily silted with volcanic debris.

"Lava flows are less hazardous than pyroclastic flows because lava travels at a very slow speed at low inclines, while pyroclastic materials are super-heated and travel at a very great speed even at low inclines," he said.

Lava flows were observed to be heading toward other gullies leading to the towns of Sto. Domingo, Daraga and Camalig, Laguerta said.

Phivolcs warned that lava or hot molten rock, which has a temperature of 600 degrees Celsius, could trigger wild fires as it reaches the southeast flank of the permanent danger zone. Surface winds blowing south could amplify this threat, it said.

Ricardo Dy, a consultant of the provincial disaster management office, recalled that a male resident died from burns after advancing lava set fire to vegetation when Mayon erupted in 1987.

"We cannot bring the firetrucks up on the slopes and water is scarce there," Dy said.

The Phivolcs report prompted Albay Gov. Fernando Gonzales to convene an emergency meeting yesterday morning at the Lignon Hill Observatory to map out strategies.

"Phivolcs is going to issue a new advisory… (Our problem concerns) those residents who might venture (into) the danger zone and (who might) be hit by pyroclastic flows," said Cedric Daep, chief of the provincial disaster management office.

He identified the 10 threatened barangays within the six-kilometer permanent danger zone as Buhian, Magapo and Buang in Tabaco City; Miisi in Daraga; Anoling, Upper Quirangay in Purok 6 and 7, Upper Cabangan and Sua in Camalig; and Baligang in Ligao City.

Authorities though have extended the danger zone to seven kilometers at the southeast flank of the 2,462-meter volcano.

"There is no evacuation order yet," Daep said, adding that such an order will be immediately issued if the volcano’s alert level is raised to 4.

Lava continued to flow from the volcano’s summit crater in the past 24 hours, while the volcano’s sulfur dioxide emission remained high at 6,586 tons per day compared to 6,099 tons last Saturday.

Steaming from the summit crater was voluminous, reflecting an active degassing from the crater area.

Seismic networks around the volcano recorded 419 tremors and 15 volcanic earthquakes.

Volcanologists said these tremors were caused by the flowing lava and the lava blocks cascading down the slopes, and the volcanic quakes by the ascending magma inside the volcano’s chamber.

Gauging from these parameters, they said Mayon continues to be at a "high level of unrest with fair probability for an explosive eruption."