MANILA, June 19 (Xinhua) -- The Philippine government is keeping a close watch on two restive volcanoes to ensure the safety of the surrounding residents, a senior government official said Sunday.
Mount Kanlaon in central Philippine Negros Island Region remains in a state of unrest after its eruption last Saturday, while Mount Bulusan in eastern province of Sorsogon erupted on June 10.
Presidential Communications Operations Office Secretary Herminio Coloma Jr. said that the Philippine Institute of Volcanology and Seismology (Phivolcs) and the National Disaster Risk Reduction and Management Council (NDRRMC) have been issuing timely alert regarding the activities of the two volcanoes.
"There are permanent exclusion zones within a certain perimeter that are being observed," he said in an interview over a state-run radio station.
After its phreatic eruption last Saturday morning, moderate steaming of plumes was seen from the summit of Mount Kanlaon, whose crater was covered with clouds, according Phivolcs.
Based on the latest Phivolcs bulletin issued at 1 p.m. on Sunday, Mount Bulusan "generated a steam-driven explosion that lasted for approximately seven minutes based on the seismic record and produced approximately 300 meter-high dirty white ash plume that drifted towards the northwest".
Alert Level 1 (abnormal) remains in effect over Bulusan Volcano. This indicates that hydrothermal processes are underway beneath the volcano that may lead to more steam-driven eruptions. The local government units and the public are reminded that entry to the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited due to the possibility of sudden and hazardous steam-driven or phreatic eruptions.
Phivolcs also said that civil aviation authorities must also advise pilots to avoid flying close to the volcano's summit as ash from any sudden phreatic eruption can be hazardous to aircraft.
Furthermore, people living within valleys and along river/stream channels especially on the 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, it added.
