Bulusan Volcano: Eruption
Situation Report
April 28, 2025
10:00 AM
Situation Overview
At approximately 04:36 AM today, a phreatic eruption occurred from the summit crater of Bulusan Volcano, which lasted for 24 minutes according to seismic and infrasound records. The eruption produced a distinct bent plume that reached an altitude of 4,500 meters above the crater. The ash cloud drifted in a west to southwest direction, resulting in reported ashfall in several areas of Sorsogon Province, including Barangays Cogon and Bolos in Irosin, Barangays Puting Sapa, Guruyan, and Buraburan in Juban, and Barangay Tulatula Sur in Magallanes.
Additionally, a pyroclastic density current (PDC), locally known as “uson,” descended the southwestern slopes of the volcano and traveled approximately three kilometers from the summit vent.
Before the eruption, a series of 53 volcanic earthquakes were recorded over a 24-hour period. Local government officials reported hearing rumbling sounds about 15 minutes before the eruption, which were also detected by infrasound sensors.
In response to the eruption, the Department of Science and Technology – Philippine Institute of Volcanology and Seismology (DOST-PHIVOLCS) has raised the alert status of Bulusan Volcano from Alert Level 0 to Alert Level 1. This indicates that the volcano is currently in a state of low-level unrest with the potential for additional phreatic eruptions following today’s event.
The 4-kilometer radius around the summit of Bulusan Volcano remains a strict no-entry zone to mitigate the risk of volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfalls, and avalanches. In addition, vigilance must be maintained in the 2-kilometer Extended Danger Zone (EDZ) on the southeast sector, due to the potential for further volcanic hazards.
Communities affected by ashfall should take necessary precautions, such as wearing protective masks or using wet fabric to avoid inhaling ash. Furthermore, residents in valleys and along river channels, particularly in the southeast, southwest, and northwest sectors of the volcano, should remain alert to the possibility of sediment-laden stream flows and lahars in the event of heavy rainfall.
Source: Philippine Institute of Volcanology and Seismology, Bulusan MDRRMO
Affected Populations
A phreatic eruption occurred at Bulusan Volcano earlier today, affecting approximately 9,000 residents across the municipalities of Irosin, Juban, and Magallanes in Sorsogon Province. The eruption resulted in widespread ashfall, which significantly impacted the National Highway connecting Bolos in Irosin and Buraburan in Juban. The ash covered roadways, hindering movement and posing a safety risk to residents and travelers.
In response to the ashfall, road clearing operations were immediately launched by local authorities, including the Sorsogon Provincial Government, the Bureau of Fire Protection, the Philippine National Police (PNP), and members of the Sorsogon Provincial Disaster Risk Reduction and Management Council (PDRRMC). These efforts are focused on clearing the affected roads to restore normalcy and ensure public safety.
A week before the eruption, the Municipal Disaster Risk Reduction and Management Office (MDRRMO) of Juban had already distributed N95 masks to residents in anticipation of volcanic activity. This preventive measure was implemented after several volcanic earthquakes had been recorded in the area, indicating heightened seismic activity around Bulusan.
Sources: National Disaster Risk Reduction and Management Council
Contacts
- Rosalia “Ross” Singcol – 09854359628
- Glenn Latoza – 09662343358