MANILA - (4TH UPDATE) Mayon Volcano shot a huge steam and ash column on Monday, the second such incident in over a week as authorities braced for a possible "hazardous eruption."
The number of evacuees could swell to 80,000 from 27,000 as authorities raised the alert one notch higher, meaning a hazardous eruption was "imminent," officials said.
Albay Governor Al Francis Bichara said the province might seek additional funding from the national government to address the disaster.
The eruption may have been "phreato-magmatic" since apart from magma or molten rocks, the volcano also spewed steam, Phivolcs Director Renato Solidum said.
Volcanic ash will be blown towards the southwest as the wind comes from northeast affecting Guinobatan, Camalig and nearby towns, he said.
The alert level was raised to level 4, one notch below the highest warning. This indicates a hazardous eruption is "imminent" and that the danger zone has been extended to an 8 kilometers radius.
"The public is strongly advised to be vigilant and desist from entering this danger zone. Civil aviation authorities must also advise pilots to avoid flying close to the volcano's summit as ash from eruptions can be hazardous to aircraft," Phivolcs said.
Mayon rises 2,460 meters (8,070 feet) above a largely agricultural region some 330 kilometers southwest of Manila. It is considered the nation's most active volcano.
Steam-driven eruptions and rockfalls began earlier this month, and the crater began glowing soon after, in what Phivolcs said was a sign of the growth of a new lava dome.
"The volcano is still inflated. There is magma beneath the volcano, which might be erupted. If the trend would show us that it’s continuously declining, we can lower the alert. As of now, we cannot lower that because that kind of trend has not started yet," Solidum told ANC.
Mayon in the past had exhibited periods of no activity in between eruptions.
"What we need to do is to make sure that people are away from the danger zone so that when that explosion happens, they will not be affected by pyroclastic flows," he added.
Solidum said the worst cases for Mayon happened in 1814 and 1897, when there was rapid ascent of magma, which generated very voluminous ash clouds and pyroclastic flows moving down.
"We don’t see that happening. The activity was not very fast from the very start," he said.