LEGAZPI CITY — Mount Bulusan in Sorsogon belched a 1.5-kilometer high ash plume cloud at around 2:55 p.m. Friday and rained ash on five villages in Juban town, a report from the Office of Civil Defense (OCD) in Bicol said.
Eduardo Laguerta, the Philippine Institute of Volcanology and Seismology (Phivolcs) resident volcanologist here, said the eruption was “phreatic,” similar to the three steam-driven explosions that happened early this week.
This time, the volcano bellowed a 1.5-kilometer high ash cloud, or about half a kilometer higher than the eruptions that took place on Tuesday and Thursday, Laguerta said in a phone interview.
On Thursday, Phivolcs’ seismic instrument recorded one explosion and one rock fall event that lasted two minutes. However, it was not observed visually due to thick clouds covering the summit. But prior to Thursday’s ash eruption, a rumbling sound was heard between 5 a.m. to 7 a.m by residents of the village of Monbon in Irosin town, the bulletin said.
OCD-Bicol spokesperson Rachelle Miranda, in a phone interview, said the ash cloud belched Friday afternoon by the volcano drifted west southwest, affecting five villages of Juban – Anog, Puting Sapa, Katanusan, Bacolod and Bura-buran – with a total population of 5,713 persons.
Volcanologists were currently checking traces of ash that fell in the villages of Juban, she said.
The collected volcanic ashes would be tested to find out if it contain magma fragments, which could indicate that magma is building up in the volcano’s vent, Laguerta said.
“if the test finds that it contains ‘juvenile magma fragments’ it would be a precursor to a much stronger eruption,” Laguerta added.
Miranda said classes in public elementary and secondary schools in Juban remained suspended following Thursday’s eruption.
Alert Level 1 remains in effect over Mount Bulusan. Phivolcs warned the villagers not to venture into the 4-km Permanent Danger Zone due to sudden phreatic explosions.
Civil aviation authorities were likewise told to advise pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption could be hazardous to aircraft.