More than a dozen barangays across three municipalities in Sorsogon were affected by ashfall after Mount Bulusan erupted again evening on Tuesday, April 29, 2025.

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) said the phreatic eruption occurred at 7:43 p.m. and lasted approximately 77 minutes.

Although the eruption plume was not visible due to cloud cover, ashfall was reported in at least 14 barangays in Irosin, Juban, and Bulan towns.

In Irosin, significant to light ashfall fell in Barangays Cogon, Tinampo, Monbon, Bolos, Gulang-Gulang, Gabao, Bulawan, and Macawayan.

Barangay Guruyan in Juban and Barangays Zone 7, Somagongsong, Beguin, and Aquino in Bulan were also affected.

Rumbling sounds were heard reportedly in Cogon and Bagsangan, Irosin, during the eruption.

PHIVOLCS also recorded 54 volcanic earthquakes as of 8:00 p.m., while sulfur dioxide emission earlier in the day reached 548 tonnes—well above the baseline level of below 200 tonnes per day.

The volcano remains under Alert Level 1, indicating low-level unrest but with the possibility of more steam-driven eruptions.

Earlier in the evening, PAGASA’s Juban Station reported that prevailing winds were blowing northeast at an average speed of 2 meters per second. 

In response, the local government of Juban deployed members of its Incident Management Team and coordinated with the Coast Guard and MDRRMO to distribute N95 masks and conduct initial assessments in affected areas like Barangay Guruyan.

Roads going in and out of Irosin were also blanketed in volcanic ash, prompting authorities to advise residents to wear face masks and avoid unnecessary travel.

Flushing operations were conducted in areas with thick ash deposits, including Bolos, Gulang-Gulang, and Tinampo, with support from the Bureau of Fire Protection, the Sorsogon provincial government, and the LGU of Casiguran.

PHIVOLCS continues to remind the public to avoid the 4-kilometer Permanent Danger Zone (PDZ) and to exercise caution within the 2-kilometer Extended Danger Zone on the southeast sector due to risks of pyroclastic flows, ashfall, and other hazards. 

Civil aviation authorities have also been warned against flying near the summit.

This latest activity follows a similar phreatic eruption recorded early Monday, April 28.