Bulusan Volcano acting up anew

LEGAZPI CITY, Philippines — After a brief period of calm, Mt. Bulusan in Sorsogon showed signs of activity anew yesterday, with 80 volcanic quakes recorded in the past 24 hours from seven during the previous three days, state seismologists said.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said that from only one quake the other day, six on Sunday and five on Saturday, Bulusan’s seismic activities shot up to two digits with accompanying volcanic quakes.

Bulusan’s emissions continued to fluctuate between 800 and 1,200 meters above the main crater and vents, with plumes ranging from 100 to 200 meters high while its ground remained inflated in the past three days.

Phivolcs said the increasing seismicity could lead to sudden and hazardous phreatic eruptions.

“Most were weak and shallow events, but may indicate that a phreatic eruption could possibly occur within the next few hours to next few days,” Phivolcs said.

Gerald Malipot, Phivolcs volcano monitoring division duty officer, said that under Alert Level 1, Bulusan could spew ash any time.

The seismic activity and other abnormal signs mean that degassing is continuing inside the volcano including possible ascent of new volcanic materials, Malipot said.

“We really need to be vigilant as a sudden phreatic eruption may occur any time. Even the sudden drop in the number of volcanic earthquake is not a guarantee that eruption is remote,” he said. “Alert Level one means the volcano is abnormal.”

The public has been reminded not to enter the four-kilometer-radius permanent danger zone due to increased possibilities of sudden and hazardous phreatic eruptions.

Phivolcs advised pilots to avoid flying close to the volcano’s summit as sudden phreatic eruption is hazardous to aircraft.

“People living in valleys and along river or stream channels especially on the southeast, southwest and northwest sector of the volcano’s edifice should be vigilant against sediment-laden stream flows and lahars during heavy and prolonged rainfall,” Phivolcs said.

At least 500 people stayed in evacuation centers in Juban for three days when Bulusan spewed ash on June 5 and 12.