The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported increased seismic activity at Bulusan Volcano in Sorsogon after recording 49 volcanic earthquakes since 3:00 a.m. on February 26, 2026.

It's 11:00 a.m. advisory on March 2, PHIVOLCS said 16 of the recorded tremors were classified as volcano-tectonic (VT) earthquakes, indicating rock fracturing at depths of three to six kilometers beneath the volcano’s northern and southeastern flanks. Other monitoring parameters, however, remained at background levels. Degassing activity from the summit crater and active vents has been described as very weak to moderate, while sulfur dioxide (SO₂) emissions were too low to be detected during the latest measurement on February 26.

Despite the uptick in seismicity, Alert Level 0 remains in effect, meaning no magmatic eruption is currently expected. However, PHIVOLCS warned that the increased earthquakes may signal active hydrothermal processes beneath the volcano that could trigger sudden steam-driven or phreatic eruptions without prior warning.

The agency reiterated that entry into the four-kilometer Permanent Danger Zone (PDZ), especially near vents on the south-southeastern slopes, is strictly prohibited due to risks of sudden explosions, rockfalls, landslides, and related hazards. Local government units were advised to review contingency and emergency response plans in case the alert status is raised.

Civil aviation authorities were also urged to caution pilots against flying near the volcano’s summit, as ash from a sudden phreatic eruption could pose hazards to aircraft. PHIVOLCS said it continues to closely monitor Bulusan’s condition and will immediately inform concerned agencies of any significant developments.