Bulusan Volcano showing increased activity

MANILA, Philippines — Bulusan Volcano in Sorsogon is showing an increase in seismic activity, with state seismologists recording at least 126 volcanic-tectonic earthquakes.

The earthquakes ranged between magnitudes-0.3 and 2.2, and were generated between one to nine kilometers beneath the north to northwestern flank of the volcano’s edifice, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).

“Degassing activity from the summit crater and active vents generated very weak to moderate volume plumes that drifted southwest to northwest,” the agency said.

Sustained seismic unrest last month indicated persistent hydrothermal activity that was likely driven by deep-seated magmatic processes and may lead to steam-driven or phreatic eruptions.

“The public is reminded that Bulusan remains under Alert Level 1, which means it is currently at sustained low-level unrest with increased chances of steam-driven or phreatic eruptions,” Phivolcs said.

Entry into the volcano’s four-kilometer-radius permanent danger zone remains prohibited, while vigilance within the two-kilometer extended danger zone on the southeast sector must be observed due to possibilities of sudden and hazardous phreatic eruptions.

“Pilots have been advised to avoid flying close to the volcano’s summit as ash generated by a sudden phreatic eruption is hazardous to aircraft. People living within valleys and along river and stream channels should be vigilant against sediment-laden stream flows and lahars during heavy and prolonged rainfall,” Phivolcs said.