Bulusan Volcano’s seismic monitoring network did not record any volcanic earthquakes during the past 24 hours. Weak emission of white steam-laden plumes that rose to 50 meters from the southeast vent before drifting southwest was observed. Precise leveling data obtained on November 20 – 29, 2017 indicated a slight deflation of the edifice, consistent with short-term deflationary trends in both tilt and continuous GPS data in the last quarter of 2017. However, the edifice remains slightly inflated since July 2016 based on continuous GPS data.

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.