The phreatic eruption that occurred in Bulusan Volcano may trigger succeeding explosions, an official of the Philippine Institute of Volcanology and Seismology (Phivolcs) warned.

Bulusan, an active volcano located in the province of Sorsogon, erupted on Sunday, June 5, prompting Phivolcs to raise its alert level status from 0 to 1. Although the eruption was “poorly visible” through cloud cover over the edifice, reports showed that a steam-rich grey plum at least 1 kilometer tall was observed from Juban, Sorsogon.

As of 12 p.m. on Sunday, ashfall has been reported in Juban and Casiguran, Sorsogon.

Amid the panic and fear brought about by the eruption, Department of Science and Technology (DOST) Undersecretary and Phivolcs Officer in Charge (OIC) Renato Solidum clarified that explosions normally occur at Bulusan even under its “normal” alert level status.

“Yung pagsabog ay sanhi ng pagkulo ng tubig sa ilalim ng crater. Ito po ay patuloy nating sinusubaybayan. Ito po ay posible talagang mangyari sa Bulusan Volcano na madalas magkaroon ng phreatic eruption, kahit nga po alert level 0, sinasabi natin na dapat iwasan ang 4-kilometer radius permanent danger zone sa Bulusan (The eruption was caused by boiling water at the bottom of the crater. We are constantly monitoring this. This is really possible to happen in Bulusan Volcano which often has phreatic eruptions, even at alert level 0, we say that the 4-kilometer radius danger zone in Bulusan should be avoided),” said Solidum in an interview over DZBB.

History of eruption and preparedness

Phreatic eruption is not a foreign occurrence at Bulusan Volcano. In fact, existing data from Phivolcs revealed that at least 21 major phreatic eruptions occurred at the volcano in the last 10 years.

Within the 10-year period, majority of the eruptions occurred in 2016. On the other hand, the agency’s data revealed that the volcano’s most recent phreatic eruption occurred on June 5, 2017 at 10:29 p.m.

“Sa ating experience sa bulkang Bulusan, once na magkaroon ng ganyang panimulang activity, ay marami pang posibleng sumunod na explosions (In our experience with the Bulusan Volcano, once there is such an initial activity, there will be more possible explosions to follow),” Solidum warned.

Meanwhile, Solidum urged local government units (LGUs) in Sorsogon to review their “preparedness plans,” considering that the ashfall may spread wherever it is blown by the wind.

“Kailangang pangalagaan ang ating mga kababayan lalo na ang mga may sakit sa baga (We need to take care our countrymen, especially those with lung disease),” he furthered.