Mt. Bulusan reaches about three kilometers above the crater's summit cloud of ash at 9:12 a.am monday.
The Philippine Institute of Volcanology and Seismology (Phivolcs) recorded the explosion, accompanied by an earthquake and rumbling sound
The earthquake lasted about 19 minutes, while the rumbling sound was heard up to 10 kilometers in Juban, Sorsogon.
State volcanologists said the explosion produced a grayish ash column that rose to about three kilometers above the summit before drifting to the southwest sector of Mt. Bulusan.Phivolcs also warned residents living near valleys and river or stream channels against sediment-laden stream flows and lava in the event of heavy and prolonged rain fall.