Increased Seismic Activity Detected at Bulusan Volcano in Sorsogon, Philippines
The Philippine Institute of Volcanology and Seismology (Phivolcs) has reported increased seismic activity at Bulusan Volcano, indicating low-level unrest. According to a bulletin issued at 8 p.m. on Tuesday, Jan. 2, a total of 116 volcanic earthquakes have been recorded by Bulusan Volcano Network (BVN) since 9 p.m. of Dec. 29, 2023. Of these, 110 were volcano-tectonic (VT) earthquakes associated with rock fracturing beneath the southern flanks at depths of two to six kilometers and six were low frequency volcanic earthquakes (LFVQ) associated with movement of volcanic fluids.
Phivolcs explained that the increased seismic activity and pressurization of the volcano edifice may indicate that hydrothermal processes are occurring beneath the volcano, which could lead to steam-driven eruptions at any of the summit vents.
Bulusan Volcano is currently at Alert Level 1, signifying low-level unrest with increased chances of steam-driven or phreatic eruptions. The public is reminded that entry into the four-kilometer radius permanent danger zone is prohibited, and vigilance is required in the two-kilometer extended danger zone on the southeast sector due to the possibility of sudden and hazardous phreatic eruptions.
Civil aviation authorities are urged to advise pilots to refrain from flying near the summit of the volcano, as any sudden phreatic eruption could pose a risk to aircraft due to the ash cloud. Additionally, residents in valleys and along river or stream channels should exercise caution in the event of heavy and prolonged rainfall coinciding with a phreatic eruption, to avoid lahars and sediment-laden stream flows.
Local government units and the general public are urged to stay informed and follow safety precautions in light of the current volcanic activity.
