(File photo)
MANILA – Most of the parameters being monitored in Mayon Volcano are low-level, but this doesn't mean its alert level status can be lowered from Level 3 (increased tendency towards hazardous eruption) to Level 2 (increasing unrest) anytime soon, the head of the Philippine Institute of Volcanology and Seismology (Phivolcs) said Thursday.
In a public briefing, Phivolcs officer-in-charge Teresito Bacolcol noted that there was only one volcanic earthquake recorded in Mayon during the 24-hour observation period.
"We are looking at various parameters, such as sustained increase or decrease in sulfur dioxide (S02) flux. As of now, the average S02 flux is 595 tonnes... We're also looking at the increase in the number of low-frequency volcanic earthquakes. There was an increase (in earthquakes) between June 25 to 27, but there was only one each between June 27 and now," he said.
Bacolcol added that even if the earthquakes would increase in number but are weak, that would still mean the volcano's alert level would be maintained.
"We are also looking at mass flux, such as longer lava flows," he said.
Phivolcs on Thursday said the lava flows have advanced to approximate lengths of 2,100 meters and 1300 meters along Mi-isi and Bonga gullies, respectively, from the summit crater. Further, "collapse debris have deposited to 3,300 meters from the crater".
Bacolcol reiterated that based on the overall parameters, they do not see that there would be a hazardous eruption.
"What we've seen are low-level parameters, weak lava flow. Again, we do not see an indication that we need to raise the volcano's alert level," he said.
He also pointed out that the alert level cannot be downgraded either.
"The volcano is still erupting (effusive eruption) so we cannot downgrade the alert level yet," Bacolcol told the Philippine News Agency.
He noted that the public should refrain from entering the 6-km radius permanent danger zone (PDZ) even if the volcano is on Alert Level 0.
Phivolcs, he said, would extend the PDZ to 7-km radius should there be sudden changes in the parameters or if they need to raise the volcano's alert level. "They are safe as long as they don't enter the PDZ," he said. (PNA)
