LEGAZPI CITY: The Philippine Institute of Volcanology and Seismology (Phivolcs) has warned the public and disaster officials to be on alert as the restive Bulusan volcano in Sorsogon may erupt again in the coming days.
On Monday morning, Bulusan exploded for 24 minutes sending a kilometer-high white grayish cloud into the air. This was the second time this month that the restive volcano erupted after October 6 and the 20th eruption since May 2015, a Phivolcs official said.
“It is the second minor eruption this month and although only steam was produced the volcano’s abnormal condition remains and it may explode again in the coming days,” Eduardo Laguerta, Phivolcs’ resident volcanologist in Bicol, said.
Bulusan volcano is one of the 22 most active volcanoes in the country.
Monday’s eruption originated from the southeast vent and produced a dirty-white to grayish ash column that reached a height of 1,000 meters.
Prior to the eruption, Bulusan’s seismic monitoring network had recorded a total of 24 volcanic earthquakes in the past 24 hours and the sulfur dioxide (SO2) emission was measured at an average of 79 tons per day.
Laguerta said the earthquakes were triggered by rock fracturing because of hydrothermal pressure that has developed in the volcano’s vent that also generated the phreatic or steam-driven explosion.
“The quakes that wobbled the volcano emitted 79 tons of sulfur dioxide which was of “normal value or indication” but because the volcano is restive and with swollen edifice it indicates continuous abnormal activities underneath,” he explained.
Alert Level 1 (abnormal), which was hoisted over Bulusan volcano in September to denote its restiveness, remains in effect.
Residents near river channels, especially on the southwest and northwest sections of the volcano’s slopes, should watch out for lahar flows during heavy and prolonged rainfall. The public is also strictly advised against entering the designated four-kilometer Permanent Danger Zone owing to the possibility of sudden and hazardous phreatic eruptions, Phivolcs said.