Mt. Bulusan underwent a second phreatic eruption last Tuesday night, causing widespread ashfall that affected the towns of Irosin, Juban, and Bulan in Sorsogon.

According to the Philippine Institute of Volcanology and Seismology (Phivolcs), the eruption started at 7:43 p.m. and lasted until 9:00 p.m.

The total height of the volcanic plume was not disclosed as it was obscured by cloud cover. However, Phivolcs noted that at least 54 volcanic earthquakes had been recorded as of 8 p.m. last Tuesday.

The sulfur dioxide (SO2) emission of the Bulusan volcano also reported an increase of up to 548 tonnes per day, higher than the baseline levels of 200 tonnes per day.

Research from the United States Geological Survey (USGS) indicates that an increase in sulfur dioxide emission suggests that the magma is near the volcano’s surface.

With the Sorsogon volcano placed under Alert Level 1, Phivolcs warned that there is a higher chance of another phreatic eruption.

Additionally, volcanic earthquakes, occurrences of ashfall, and the release of poisonous gas such as sulfur dioxide were also warned.

The entry of residents within the volcano’s 4-kilometer-radius Permanent Danger Zone and the 2-kilometer Extended Danger Zone within Bulusan’s southeastern region is prohibited.

Hours after the phreatic eruption, the Sorsogon Provincial Police Office reported that all roads in the towns of Casiguran and Juban are passable. However, they advised that travelers continue wearing face masks.

Presidential Communications Office Undersecretary Claire Castro said that there are sufficient funds for the volcano evacuees.

“The Department of Social Welfare and Development (DSWD) reported that there are standby funds available, and that prepositioned relief stockpiles are in place,” she said.