• GILBERT P. BAYORAN
After recording an elevated volcanic sulfur dioxide gas emissions from the crater of Mt. Kanlaon, the Philippine Institute of Volcanology and Seismology (Phivolcs) also noticed an increased seismic activity of the volcano.
A total of 90 volcanic earthquakes were recorded by the Kanlaon Volcano Network between 3 p.m. of July 2 and 12 noon of July 3.
According to Phivolcs, most of these earthquakes were generated within a depth of 20 kilometers beneath the southeastern sector of the edifice, and consist of five volcano-tectonic events that are produced by rock fracturing and 85 weak low-frequency events that indicate the movement of volcanic fluids.
In addition, volcanic sulfur dioxide gas emission from the summit crater has been persistently elevated since the June 3 eruption, currently averaging 3,254 tonnes per day since then and reaching 5,083 tonnes per day on July 2, the Phivolcs advisory further said.
The normal volcanic sulfur dioxide gas emissions at Mt. Kanlaon is only 300 tonnes per day.
Ground deformation data from continuous global positioning system and electronic tilt measurements have been recording an ongoing inflation that began between April and July 2023 and a longer-term inflation of the entire edifice since March 2022, indicating slow but sustained pressurization within the volcano.
The overall monitoring parameters indicate that magmatic processes beneath volcano may be driving current unrest, causing increased volcanic earthquake activity, persistently high concentrations of volcanic gas emission and swelling of the edifice, Phivolcs further stated.
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, it added.
It also reminded the public that Alert Level 2 (increasing unrest) prevails over Mt. Kanlaon, and discouraged the entry into the four kilometer-radius permanent danger zone to minimize risks from volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfall and others. | GB
