LEGAZPI CITY, Albay, Philippines -- (UPDATE 2) The Philippine Institute of Volcanology and Seismology has raised the alert level on Mayon Volcano from three to four after it exhibited abrupt increase in seismicity, accompanied by rumbling sounds and other factors indicating a possible eruption in days.
“All the bases are already there and we have no choice but to raise the alert status from level 3 to level 4, barely six days after it was upgraded from alert level 2 last Monday,” resident volcanologist Eduardo Laguerta said.
From 8 a.m. to 2 p.m. Sunday, 463 volcanic earthquakes were recorded, and these were considered characteristic of a heightened activity near to an explosive eruption, Laguerta said.
He said Mayon manifested signs of a strombolian eruption similar to that of 2001.
A strombolian type of eruption is characterized by fountaining of lava from the crater, reaching several kilometers upwards, and raining of ashfall.
“This nearing explosive eruption is no longer comparable to the protracted type in 2006 eruption with only lava flows oozing at the crater down to Mabinit, Legazpi City, six kilometers from the crater,” Phivolcs Director Renato Solidum said in a press briefing here Sunday afternoon.
He said the parameters indicated that the volcano would expel big boulders.
Solidum said they received reports that residents of Sta. Misericordia in Sto. Domingo town heard rumbling sounds at about 2:55 p.m.
To ensure the safety of the public, the Phivolcs is recommending an extended danger zone of 8 kilometers from the summit at the southern sector and 7 km at the northern sector.
Even areas just outside of this extended danger zone should prepare for evacuation in the event of explosive eruptions.
The past 24-hour observation period showed that the advancing lava flow reached around 4.5 kilometers downslope from the crater along the Bonga-Buyuan gully.
Sulfur dioxide emission increased from 2,034 tons per day to 7,024 tons per day during the same observation period.
But the Provincial Disaster Coordinating Council had already moved well ahead of this alert status declaration by adopting a calibrated response and preparation for alert level 4 even as Mayon was just under alert status level 3 during the past six-day period.
Governor Joey Salceda stressed the need to double patrolling in the recommended extended and the permanent danger zones around Mayon because of the danger of pyroclastic flows, rockfall and ashfall.
Salceda confirmed reports many people were still returning to their farms and homes. "But we will never give up on persuading these people and bringing them to their respective evacuation centers," Salceda said.
