• GILBERT P. BAYORAN
The Philippine Institute of Volcanology and Seismology recorded elevated volcanic sulfur dioxide (SO2) gas emissions from the summit crater of the Kanlaon Volcano in Negros Island on June 28.
PHIVOLCS logged an average of 5,397 tons of volcanic SO2 gas emissions – the highest emission from the volcano recorded since instrumental gas monitoring began.
Mount Kanlaon has been degassing increased concentrations of volcanic SO2 this year, at an average rate of 1,897 tonnes/day, but emissions since the June 3 eruption have been particularly elevated at a current average of 3,175 tonnes/day, PHIVOLCS said.
It noted an increase of gas emissions from 2,147 tons on June 25, to 2,774 in June 26, to 3,299 in June 27.
On June 30, PHIVOLCS also logged 14 volcanic quakes at Kanlaon.
“Ground deformation data from continuous GPS and electronic tilt measurements have been recording medium-term inflation of the Kanlaon edifice since March 2022 and a shorter-term inflation of the eastern flank since 2023, indicating slow but sustained pressurization within the volcano.”
These overall monitoring parameters indicate that magmatic processes beneath the volcano “may be driving current unrest, causing persistently high concentrations of volcanic gas emission, swelling of the edifice, and the occasional volcanic earthquake activity,” the PHIVOLCS advisory said.
It reminded the public that Alert Level 2, or increasing unrest, prevails over Mount Kanlaon.
“This means that there is current unrest driven by shallow magmatic processes that could eventually lead to explosive eruptions, or even precede hazardous magmatic eruption at the summit crater.”
PHIVOLCS reiterates that entry into the four-kilometer-radius Permanent Danger Zone (PDZ) is prohibited so as to minimize risks from volcanic hazards, such as pyroclastic density currents, ballistic projectiles, rockfall, and others.
Almost all of more than 9,000 residents affected by the Kanlaon phreatic eruption on June 3 have returned to their respective homes, with 51 families, composed of 116 individuals who were residing at the permanent danger zone, still staying at the evacuation center in La Castellana, Negros Occidental.*
