|BULUSAN VOLCANO BULLETIN 25 September 2011 8:00 A.M.|
|Monday, 26 September 2011 01:41|
Bulusan Volcano’s (12.7667°N, 124.0500°E) seismic network did not detect any volcanic earthquake during the past 24 hours. Weak emission of white steam that reached a height of 50 meters above the active vents and drifted to the east-northeast could be observed from the southwest thermal vents. Steaming activity at other thermal vents varied from wispy to weak. Ground deformation survey (precise leveling) conducted last 16 - 20 August 2011 yielded no significant change at Inlagadian leveling line on the north-northeast flank but yielded slight inflation at Mapaso leveling line on the south-southeast flank, relative to the previous survey last 07 - 09 June 2011.
Bulusan Volcano’s status remains at Alert Level 1, meaning that current volcanic activity is driven by shallow hydrothermal processes. Entry into the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited due to sudden steam and ash eruptions. Due to the prevailing wind direction, residents in the northwest and southwest sectors of the volcano are reminded to take precautions against ashfall from sudden eruptions. Civil aviation authorities must also warn pilots to avoid flying close to the volcano’s summit as ejecta from sudden eruptions may be hazardous to aircraft. If possible, aircraft should avoid airspace west of the volcano as volcanic ash is likely to be dispersed in this direction by prevailing winds. Furthermore, people living within valleys and along 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 development will be relayed to all concerned.