Bulusan Volcano shows signs of ‘increased activity’ anew — Phivolcs

Published June 29, 2022, 5:27 PM

by Ellalyn De Vera-Ruiz

Bulusan Volcano in Sorsogon (PIXABAY / FILE PHOTO)

The Philippine Institute of Volcanology and Seismology (Phivolcs) on Wednesday, June 29, said it has detected 213 volcanic earthquakes in Mt. Bulusan since June 24–a manifestation of increased activity that could lead to another eruption.

“The strongest of these (earthquakes) was a magnitude 3.5 volcanic earthquake at 11:27 p.m. on June 24 that was also recorded by the Philippine Seismic Network, and felt at Intensity III in Irosin and Bulusan in Sorsogon,” Phivolcs said in an advisory on Wednesday.

“At 1:39 p.m. today (June 29), a magnitude 2.3 imperceptible volcanic earthquake was recorded by the Bulusan Volcano Network,” it added.

Phivolcs said the 3.5-magnitude and 2.3-magnitude earthquakes originated from the southsoutheastern flank of Bulusan edifice at depths of approximately 3 kilometers.

In addition, short-term ground deformation monitoring data based on continuous electronic tilt has been recording inflation of the southern flanks since June 20, 2022, consistent with continuous GPS recording of inflation of the southern flanks since March 2022, Phivolcs added.

“These monitoring parameters warn of the possibilities of renewed eruptive activity from the Bulusan summit and potentially from the vents of its southern sides,” it pointed out.

Phivolcs said the active volcano remains under Alert Level 1, which means it is still in an “abnormal” condition.

Bulusan Volcano’s status has been raised from Level 0 to Level 1, following a phreatic eruption on June 5. It had another phreatic eruption on June 12.

In an advisory issued on Monday, June 20, Phivolcs warned of another possible eruption “within the next few hours to next few days.”

Phivolcs said that entry into the four-kilometer permanent danger zone is strictly prohibited due to possible sudden steam-driven or phreatic eruptions.

Meanwhile, the public is advised to remain vigilant when entering the two-kilometer extended danger zone, which is in the southeast sector of Bulusan Volcano.

Furthermore, people living within valleys and along river/stream channels especially on the southeast, southwest and northwest sector of the edifice were advised to be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall should another phreatic eruption occurs.