Phivolcs raises alert level in Mt. Bulusan

Mount Bulusan has continued to exhibit signs of restiveness after it was jolted by 72 volcanic quakes and 43 low frequency events for the past four days prompting the Philippine Institute of Volcanology and Seismology (Phivolcs) to raise its alert status to Level 1.

A Phivolcs advisory said seismic instrument on Tuesday, July 7 recorded at least 19 volcanic quakes for the past 24-hour period. The quakes were associated with weak and shallow hydrothermal or magmatic gas activity within Bulusan’s edifice.

Very weak emission of white steam-laden plumes from the lower southeast vent was also observed by Philvolcs.

Bulusan Volcano’s monitoring network has recorded a total of 53 volcanic earthquakes since July 3 including 43 low frequency events.

Phivolcs’ Global Positioning System (GPS) instrument measured a slight bulging on the volcano’s edifice since February indicating that deep-seated degassing or hydrothermal or magmatic event was developing underneath the volcano.

Due to the abnormalities displayed by the volcano, Phivolcs reiterated its warning to the public not to enter the four-kilometer radius Permanent Danger Zone (PDZ) including the two-kilometer Extended Danger Zone (EDZ) on the southeastern sector of the volcano due to sudden and hazardous phreatic eruption.

It also informed civil aviation authorities to advise airplane pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to aircrafts.

Mount Bulusan in Sorsogon province recorded its last major eruptive event in December 2016 where it had a phreatic eruption, sending an ash plume two kilometers into the sky.