Phivolcs watching Bulusan Volcano after three quakes in 24 hours

July 8, 2020

The Philippine Institute of Volcanology and Seismology (Phivolcs) is closely monitoring the Bulusan volcano after it was placed under alert level one or in an abnormal condition last Sunday.

"In the past 24-hour period, Bulusan Volcano’s monitoring network recorded three volcanic earthquakes that are associated with weak and shallow hydrothermal or magmatic gas activity within the edifice," Phivolcs said on Wednesday.

"Weak emission of white steam-laden plumes from the lower southeast vent was observed," it stated.

"Ground deformation data from continuous GPS measurements also indicate a short-term inflation of the edifice since late February 2020," it added.

Phivolcs noted that the monitored parameters indicate that "volcanic processes are underway beneath the edifice that may be caused by deep-seated degassing or hydrothermal activity or magmatic intrusion."

"Phivolcs is closely monitoring Bulusan volcano’s condition and any new development will be communicated to all concerned stakeholders," it stated.

Phivolcs reminded local government units and the public that the "entry into the four-kilometer radius permanent danger zone is strictly prohibited and that vigilance within the two-kilometer extended danger zone 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", Phivolcs said.

"Furthermore, people living within valleys and along river or 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," it added. Robina Asido/DMS