Bulusan Volcano’s monitoring network recorded thirteen (13) volcanic earthquakes during the 24-hour observation period. Weak emission of white steam-laden plumes that rose 20 meters high that crept upslope from the lower southeast vent was observed. Ground deformation data from continuous GPS measurements indicate a cycle of inflation followed by deflation of the edifice beginning late February 2020, while the long-term trend since May 2019 denote that the edifice is still deflated. These parameters indicate that volcanic processes are underway beneath the edifice that may be caused by deep-seated degassing or hydrothermal activity or magmatic intrusion.
Alert Level 1 (Abnormal) status prevails over Bulusan Volcano, which means that it is currently in an abnormal condition. Local government units and the public are reminded that entry into the four-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited and that vigilance within the two-kilometer Extended Danger Zone (EDZ) on the southeastern sector 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.