By Alec Go
The Philippine Institute of Volcanology and Seismology (Phivolcs) notified the public in an advisory on Wednesday afternoon, June 29, of Bulusan Volcano’s increased activity.
Phivolcs said the Bulusan Volcano Network (BVN) recorded 213 volcanic earthquakes since 5:00 a.m. of June 24, including a magnitude 3.5 volcanic quake recorded by the Philippine Seismic Network (PSN) at 11:27 p.m. on June 24 felt at intensity III in Irosin and Bulusan.
Another magnitude 2.3 quake was recorded at 1:39 p.m. on June 29 on the south-southeastern flank of the Bulusan edifice with an approximately three-kilometer depth.
“Short-term ground deformation monitoring based on continuous electronic tilt has been recording inflation of the southern flanks since 20 June 2022, consistent with continuous GPS recording of inflation of the southern flanks since March 2022,” the Phivolcs noted.
“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 added.
BULUSAN VOLCANO BULLETIN
29 June 2022
5:00 PM#BulusanVolcano #DOSTPHIVOLCS pic.twitter.com/e0U8or5e2i— PHIVOLCS-DOST (@phivolcs_dost) June 29, 2022
Bulusan volcano, currently with an inflated edifice, remains under Alert Level 1 at low-level unrest.
Authorities are prohibiting the entry into the four-kilometer radius of the permanent danger zone, while vigilance is required within the two-kilometer extended danger zone on the southeast sector “due to the increased possibilities of sudden and hazardous phreatic eruptions.”
Air personnel were also advised to “avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to aircraft.”
“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 should phreatic eruption occur,” Phivolcs said.
Based on Phivolcs’ Bulusan 24-hour observation on June 29 morning, a total of 107 volcanic earthquakes were recorded, with 630 tonnes of sulfur dioxide emission on June 28, and plume emissions reaching 100 meters high. – gb
