SORSOGON CITY, May 8 — A possible phreatic or stream-driven explosion of Mt. Bulusan maybe forthcoming after the volcano exhibited steam and ash explosions on May 1 and another stream-driven explosion on May 6. With this prospect, residents within valleys and along rivers and stream channels are warned to be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall.
The Philippine Institute of Volcanology and Seismology raised its alert level to Alert Status 1 yesterday (May 7) after seeing occurrences of localized earthquakes, steam or gas activity. The Phivolcs sees these as hydrothermal, magmatic, or tectonic disturbances. Entry to the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited with the possibility of sudden and hazardous stream-driven eruptions.
The steam and ash explosion which occurred at 9:46 in the evening of May 6lasted for about 4 minutes. An explosion from a vent on Bulusan’s northwest upper slopes plumed ashes at 250 meter high. Affected areas include Sitio Tulay of Brgy. Bagsangan, Cogon, Monbon, and Tinampo in Irosin town, Sorsogon.