Alert Level 1 has been raised over Bulusan Volcano after its phreatic eruption on Sunday morning, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).
In a bulletin, PHIVOLCS said the phreatic eruption that occurred at 10:37 a.m. lasted approximately 17 minutes, and was recorded by the seismic and infrasound monitoring by the Bulusan Volcano Network (BVN).
"The event was poorly visible through cloud cover over the edifice although a steam-rich grey plume at least 1 kilometer tall was observed from Juban, Sorsogon, and was subsequently observed to drift west," said PHIVOLCS.
Ashfall was also recorded in Juban and Casiguran, Sorsogon, said the agency, while 77 volcanic earthquakes in the past 24 hours have been reported prior to the eruption.
"Alert Level 1 is now raised over Bulusan Volcano, which means that it is currently in an abnormal condition," declared PHIVOLCS.
It urged local government units to prohibit entry in the four-kilometer Permanent Danger Zone, while vigilance in the two-kilometer Extended Danger Zone must be exercised. It also advised plans to avoid flying close to the volcano's summit as ash from the 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 a phreatic eruption occur," it said.
PHIVOLCS assured that it is closely monitoring the volcano and any new development will be reported.