Mount Bulusan in Sorsogon spews a 1.5-kilometer high ash column in a steam-driven or phreatic explosion
© Crisanto GamisMount Bulusan in Sorsogon spews a 1.5-kilometer high ash column in a steam-driven or phreatic explosion
Mount Bulusan in Sorsogon, Bicol spewed a 1.5-kilometer- high ash column Friday afternoon, in a steam-driven explosion.

According to the Provincial Disaster Risk Reduction and Management Office (PDRRMO) in Sorsogon, the phreatic explosion occurred at approximately 4:54 p.m. Friday, and lasted for close to four minutes.

The dark gray ash plume expelled by the volcano drifted towards the northeast, causing ash to fall in Casiguran, Juban, Barcelona, and Gubat.

Alert Level 1, indicating abnormal activity, remains over Bulusan Volcano, said the Philippine Institute of Volcanology and Seismology (Phivolcs) in its 6 p.m. notice.

This indicates that hydrothermal processes are underway beneath the volcano, which may lead to more steam-driven eruptions, the agency said.

It also reminded the public not to enter the 4-kilometer radius Permanent Danger Zone (PDZ).

Bicolanos watch as Bulusan Volcano spews a 1.5-kilometer high ash column in a steam-driven or phreatic explosion.
© Leovlyn PuranBicolanos watch as Bulusan Volcano spews a 1.5-kilometer high ash column in a steam-driven or phreatic explosion.
Pilots have also been asked to steer clear of the volcano's summit to avoid ash from any sudden explosions.

People living within valleys and along river or stream channels southwest and northwest of the volcano should also guard against sediment-laden stream flows and lahar in the event of heavy and prolonged rainfall.

Phivolcs said it will continue to monitor volcanic activity.

Meanwhile, Alert Level 1 also remains in effect over the nearby Mayon Volcano in Albay.

While no magmatic eruption is expected, said Phivolcs, the public should steer clear of the 6-kilometer PDZ due to the danger presented by possible rockfalls, landslides, sudden ash puffs, and steam-driven explosions from the summit.