LEGAZPI CITY, Nov. 6, 2010 - Sorsogon province's Mt. Bulusan spewed a grayish ash column 600 meters high Saturday, prompting the Philippine Institute of Volcanology and Seismology (Phivolcs) to raise Alert Level 1.
Phivolcs reported observing explosions as thick ash clouds hovered over the volcano's summit.
Seismic instruments recorded a 57-second ash explosion at about 8:11 a.m. Saturday, Phivolcs noted.
In its bulletin, Phivolcs said its seismic instruments already recorded four volcanic earthquakes during the past 24 hours.
