c41ba6f4_Bulusan_Volcano_Alert_Signals__ALERT_LEVEL
[CRITERIA] Sustained increases in the levels of volcanic earthquakes, some may be perceptible. Occurrence of low-frequency earthquakes, volcanic tremor, rumbling sounds. Forceful and voluminous steam/ash ejections. Sustained increases in SO2 emission rates, ground deformation/swelling of the edifice. Activity at the summit may involve dome growth and/or lava flow, resultant rockfall. Magma is near or at the surface, and activity could lead to hazardous eruption in weeks. Danger zones may be expanded up to eight (8) kilometers from the active crater. [ALERT LEVEL] 
3 High Level of Volcanic Unrest
Bulusan Volcano Alert Signals
ALERT LEVEL