THE Philippine Institute of Volcanology and Seismology (Phivolcs) issued a warning after it noticed restive activity involving the Kanlaon Volcano.
In an advisory released by Phivolcs, it noted a slight increase in seismic activity and volcanic gas flux from the volcano, with a total of 28 volcanic earthquakes between February 11 and 13.
Phivolcs reported the tremors' energy ranged between Magnitudes 0.7 to 2.2, all of which occurring at shallow depths of 10 kilometers. The quakes were epicentered across the northern and eastern portions of the edifice.
Monitoring equipment at the volcano also noted a higher emission of sulfur dioxide gas with 1,130 metric tons/day, which they noted was the highest recorded value this year following a trend since June 2020 of emissions higher than background levels of 300 metric tons/day.
Ground deformation data from continuous Global Positioning Systems (GPS) and electronic tilt measurements have been recording slight inflation of the lower and middle slopes since June 2020, indicating slow pressurization within the volcano.
"These parameters could indicate hydrothermal, tectonic or even deep-seated magmatic processes occurring beneath the edifice," Phivolcs said.
The government agency is warning everyone not to enter the volcano's four-kilometer permanent danger zone as sudden hazardous phreatic eruptions may occur without warning.
Phivolcs has also told the Civil Aviation Authority of the Philippines to advise pilots to avoid flying close to the volcano's summit as ejecta from any sudden phreatic eruption can be hazardous to aircraft.
Phivolcs is still retaining the "Alert Level 1" status for the Kanlaon Volcano.
Kanlaon volcano last erupted on March 29, 2016m which lasted approximately 12 minutes and produced a volcanic plume 1,500 meters above the crater. No one was hurt during the eruption.