The Philippine Institute of Volcanology and Seismology (Phivolcs) on Sunday, May 26, recorded increased seismic activity in Kanlaon Volcano.
In a 5 p.m. bulletin, Phivolcs reported that between 1:35 p.m. and 4:30 p.m., 24 volcano-tectonic (VT) earthquakes were monitored through the Kanlaon Volcano Network.
"These earthquakes ranged in energy from 0.8 to 2.3 and occurred at depths of 0 to 6 kilometers beneath the western flank of the Kanlaon volcanic edifice," Phivolcs said.
Meanwhile, the sulfur dioxide (SO₂) gas emission from the volcano's summit crater has increased since January 1, averaging 1,291 tonnes per day.
The most recent measurement on May 26 showed an average of 2,003 tonnes per day.
Phivolcs emphasized that data from continuous Global Positioning System (GPS) and electronic tilt measurements show ongoing inflation, starting between April and July 2023, and longer-term inflation of the entire edifice since March 2022.
"While monitoring parameters in the past months have been consistent with shallow hydrothermal activity driven by degassing of deeper magma, ongoing VT earthquake activity indicates shallow rock-fracturing on the edifice, which may lead to further unrest," Phivolcs said.
Alert Level 1
Phivolcs said the Kanlaon Volcano would remain at Alert Level 1 (low-level unrest).
As a result, Phivolcs prohibits the public from entering the four-kilometer Permanent Danger Zone (PDZ) due to increased chances of sudden and hazardous phreatic eruptions occurring without warning.
It also prohibits pilots of any aircraft from flying close to the volcano.
These prohibitions are due to potential hazards such as sudden steam-driven or phreatic eruptions.