Volcano Enters Low-Level Unrest Period

Phivolcs Raises Alert After Weeks of Seismic Swarms

Bulusan Volcano in Sorsogon province was placed under Alert Level 1 on Sunday, March 22, marking a significant shift from its previous dormant status. The Philippine Institute of Volcanology and Seismology (Phivolcs) announced the upgrade after monitoring weeks of increased seismic activity beneath the volcano's edifice. Prior to this elevation, Bulusan had been under Alert Level 0, indicating normal background activity. The transition to Level 1 signals that the volcano has entered a state of low-level unrest, with an elevated probability of phreatic or steam-driven eruptions occurring without warning.

What Alert Level 1 Means for Local Communities

The classification of Level 1 comes with clear implications for public safety. According to Phivolcs, this alert means the public should refrain from entering the designated 4-kilometer Permanent Danger Zone around the volcano's summit. Phreatic eruptions are particularly unpredictable because they occur when groundwater is rapidly heated by magma, causing violent steam explosions that can eject rocks, ash, and volcanic debris. Unlike magmatic eruptions that often give longer windows of warning, phreatic events can materialize with little to no precursor indication, making vigilance essential for communities living near the volcano.

Heightened Monitoring and Preparedness Measures

Government Agencies on Standby

Local government units in Sorsogon have begun coordinating with national agencies to ensure that evacuation plans are in place should activity escalate further. Disaster risk reduction offices are urged to monitor volcanic bulletins issued by Phivolcs and communicate any developments to residents living in high-risk barangays. The Office of Civil Defense and regional police forces are also prepared to support any necessary evacuation operations, though no orders for forced evacuation have been issued as of this writing.

Residents Advised to Stay Informed

Phivolcs emphasized that residents must avoid speculating about volcanic behavior and instead rely on official updates. The institute maintains a network of seismometers and monitoring equipment around Bulusan that provide real-time data on ground deformation, gas emissions, and seismic patterns. Citizens near the volcano should listen to local authorities and monitor Phivolcs advisories for any changes in alert status. Wearing dust masks during ashfall events and securing livestock in covered shelters are among the practical steps recommended for those within the danger zones.

Bulusan's History of Sudden Eruptions

A Volcano Known for Unpredictability

Mount Bulusan has a documented history of phreatic eruptions that have surprised observers in the past. The volcano's frequent sudden explosions contrast with the more gradual buildup seen at other Philippine volcanoes like Taal or Mayon. Its propensity for generating ash plumes with little warning has made it a persistent concern for Phivolcs and local disaster managers. The current unrest underscores the importance of respecting hazard boundaries and maintaining readiness even during periods when the volcano appears quiet from the outside.

Ongoing Vigilance as Situation Evolves

Phivolcs continues to closely observe Bulusan's activity and will provide updates as conditions change. The public is reminded that Alert Level 1 is the lowest tier of volcanic warning, yet it still demands respect and adherence to safety protocols. Cooperation between government agencies, local officials, and residents will be crucial in minimizing risks as the situation develops.