Bulusan erupts; alert level raised

MANILA, Philippines, April 29 ------ The Philippine Institute of Volcanology and Seismology has placed Mt. Bulusan under Alert Level 1 following a phreatic eruption early morning yesterday. According to Phivolcs director Teresito Bacolcol, Alert Level 1 means that the volcano is undergoing low level of unrest. “Our recommendation is there should be no residents inside the four-kilometer permanent danger zone of Bulusan Volcano,” Bacolcol said in a radio interview.

According to him, the phreatic eruption occurred at 4:36 a.m. and lasted for 24 minutes. He added that the permanent danger zone will be extended to six kilometers once the situation is elevated to Alert Level 2. “There is always the possibility (of increasing to Alert Level 2) but as to when, we don’t know yet, but we are closely monitoring the activity of Bulusan. If there would be changes in its parameters, then we may raise from Alert Level 1 to Alert Level 2,” Bacolcol added.

According to Bacolcol, Mt. Bulusan last erupted in June 2022. Based on the state bureau’s report, the phreatic eruption produced a bent plume that rose 4,500 meters above the crater before drifting west to southwest. A pyroclastic density current or “uson” descended the southwestern slopes and traveled within three kilometers from the summit vent. Bacolcol added that ashfall was reported in barangays Cogon and Bolos in Irosin, Puting Sapa, Guruyan and Buraburan in Juban and Tulatula Sur in Magallanes – all in Sorsogon. “Prior to the eruption, a total of 53 volcanic earthquakes were recorded over the 24-hour period yesterday. Rumbling sounds were reported by local government officials approximately 15 minutes before the eruption and were recorded by infrasound sensors,” Phivolcs said.

Bacolcol warned of more phreatic eruptions amid the ongoing unrest of Bulusan. “Furthermore, people living within valleys and along river and stream channels, especially on the southeast, southwest and northwest sector of the edifice should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall should phreatic eruption occur,” Phivolcs said.

The Department of Health reminded affected residents in Sorsogon to wear N95 face masks, safety goggles, long sleeves and pants as a precaution against ashfall. The agency also advised people to prepare water, food, clothing, first aid and medicines. Meanwhile, the Civil Aviation Authority of the Philippines issued a Notice to Airmen for Bulusan Volcano, effective April 28, 8:29 a.m. until April 29, 4:36 a.m. CAAP advised pilots to avoid flying near the volcano, with vertical limits from the surface up to 21,000 feet.

Source: philstar.com