MANILA, Philippines – Sorsogon’s Bulusan Volcano remains under Alert Level 0, but state volcanologists warned that “there are increased chances of steam-driven or phreatic eruptions occurring at the crater or summit area.”

The Philippine Institute of Volcanology and Seismology (Phivolcs) said in an advisory on Thursday, September 21, that it has recorded 22 volcano-tectonic earthquakes since 5 am of Wednesday, September 20.

The strongest earthquakes ranged from magnitude 0.1 to 1.5 and “originated between 1 [and] 5 kilometers beneath the southern sector of Bulusan Volcano,” added Phivolcs.

The agency also observed weak to moderate degassing at the crater and vents this week.

But sulfur dioxide emission only averaged 100 tons per day on Thursday, “well within baseline levels.”

Bulusan’s edifice has been inflated or swollen since December 2022.

Phivolcs reminded the public not to enter the 4-kilometer-radius permanent danger zone surrounding the volcano, due to the risk of phreatic eruptions, rockfalls, and landslides.

Last August 1, the agency had warned that changes in Bulusan’s condition could lead to “further unrest.”

The volcano has been under Alert Level 0, the lowest level, since January 18. – Rappler.com