THE Philippine Institute of Volcanology and Seismology (Phivolcs) has placed Bulusan Volcano under Alert Level 1 status following its explosion Sunday, June 5, 2022.Alert Level 1 (low level unrest) means that the volcano is currently in an abnormal condition, said Phivolcs.It said a phreatic eruption occurred at the volcano summit at 10:37 a.m. Sunday and it lasted approximately 17 minutes.“The event was poorly visible through cloud cover over the edifice although a steam-rich grey plume at least one kilometer tall was observed from Juban, Sorsogon and was subsequently observed to drift west,” said Phivolcs in an advisory.It added that as of 11:40 a.m. Sunday, ashfall has been reported in Juban and Casiguran, Sorsogon.Prior to Bulusan’s eruption Sunday, the Bulusan Volcano Network recorded 77 volcanic earthquakes in the past 24-hour observation period, said the agency.“Ground deformation data from continuous GPS monitoring indicate that the Bulusan edifice has been inflated since February 2021, while electronic tilt monitoring recorded a sudden but isolated inflation of the southeast lower slopes only since April 2022,” it said.“These parameters indicate that volcanic processes are underway beneath the edifice that are likely caused by shallow hydrothermal activity,” it added.Phivolcs warned local government units and the public against entry into the four-kilometer radius Permanent Danger Zone (PDZ).It also said that vigilance must be observed in the two-kilometer Extended Danger Zone (EDZ) on the southeast sector of the volcano due to the increased possibilities of sudden and hazardous phreatic eruptions.It also advised civil aviation authorities to inform pilots to avoid flying close to the volcano’s summit, as ash from any sudden phreatic eruption can be hazardous to aircraft.People living within valleys and along river/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 added.The agency assured that it is closely monitoring the Bulusan Volcano’s condition. (LMY)