Philippine Institute of Volcanology and Seismology, Powered by Joomla!
Tuesday, 22 February 2011 07:18

Bulusan Volcano’s (12°46.2’N, 124°03’E) seismic network recorded sixteen (16) volcanic earthquakes during the past 24 hours. Two of these events, which occurred at 9:12AM and 10:27 AM yesterday, were recorded as explosion type earthquakes. The first explosion was accompanied by rumbling sound which was heard up to ten (10) kilometers away in the town of Juban, Sorsogon. This produced a grayish ash column that rose up to about three (3) kilometres above the summit before drifting to the southwest. Field investigation confirmed the presence of ash deposits in the towns of Irosin (up to 5mm) and Bulan (up to 3mm) in Sorsogon. Traces of ash deposits were also reported in the municipalities of Juban and Magallanes, also in Sorsogon, and in Masbate City, Masbate.

Bulusan Volcano’s status remains at Alert Level 1.  This means that the source of activity is hydrothermal and shallow. Entry to the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited, since the area is at risk to sudden steam and ash explosions.  Due to the prevailing wind direction, residents in the northwest and southwest sectors of the volcano are reminded to take precautions against ashfalls.  Civil aviation authorities must also warn pilots to avoid flying close to the volcano’s summit as ejected ash and volcanic fragments from sudden explosions may be hazardous to aircraft.  Furthermore, people living near valleys and river/stream channels should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall.  DOST-PHIVOLCS is closely monitoring Bulusan Volcano’s activity and any new significant development will be immediately relayed to all concerned.