Bulusan Volcano’s seismic monitoring network did not detect any volcanic earthquake during the 24-hour observation period. Wispy emission of white steam-laden plumes from the active vents was observed. Ground deformation from Precise Leveling data obtained on 29 August – 05 September 2019 indicate a slight inflation of the edifice relative to the 21 June – 01 July 2019 surveys. However, data recorded by Bulusan’s continuous GPS network show continued deflation of the edifice since July 2018.
Alert Level 1 (abnormal) status remains in effect over Bulusan Volcano, which means that it is currently in a state of unrest probably driven by hydrothermal processes that could generate steam driven or phreatic eruptions. Local government units and the public are reminded that entry into the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited and that vigilance in the Extended Danger Zone (EDZ) must be exercised due to the increased possibilities of sudden and hazardous phreatic eruptions. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to aircraft. Furthermore, people living within valleys and along river/stream channels especially on the southeast, southwest and northwest sector of the edifice 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 condition and any new development will be communicated to all concerned stakeholders.