A total of seventy-two (72) volcanic earthquakes was recorded on Kanlaon Volcano in Negros Island between 12 a.m. and 12 p.m. on Monday, May 12, 2025.
"These events ranged in strength between ML0.3 and ML3.1 and were generated at 0 to 8 kilometers depths beneath the northern and northwestern flanks of the volcanic edifice. A total of one hundred thirty-five (135) volcanic earthquakes have been recorded since 12:00 AM of 11 May 2025, including relatively strong volcano-tectonic or VT earthquakes," DOST-PHIVOLCS said in an advisory issued at 1:30 p.m.
"VTs are generated by rock fracturing processes and the increase in VT activity strongly indicates progressive rock-fracturing beneath the volcano as rising magma or magmatic gas drives a path towards the surface. Volcanic sulfur dioxide (SO2) gas emissions from the summit crater of Kanlaon based on campaign mDOAS measurements yesterday, 11 May 2025, averaged 554 tonnes/day. There has been a decline in the average sulfur dioxide emission from 4,144 since 3 June 2024 to 2,114 since 01 April 2025. These parameters indicate that the blockage of volcanic gas emission (or closed-system degassing) may result in pressurization and swelling of the edifice potentially leading to moderately explosive eruption at Kanlaon," the advisory reads in full.
Alert Level 3 (magmatic unrest) prevails over Kanlaon, which means that the volcano is in a state of magmatic unrest.
"Currently there are increased chances of short-lived explosive eruptions occurring that could generate life-threatening volcanic hazards. It is recommended that communities within a 6-km radius from the summit crater remain evacuated due to the danger of pyroclastic density currents or PDCs, ballistic projectiles, ashfall, rockfall and other related hazards. Local government units must continue to prepare their communities within the PDC hazard zone for subsequent evacuation in case unrest further escalates and hazardous worst-case explosive eruption becomes imminent. Increased vigilance against potential syn-eruption lahars and sediment-laden streamflows in channels draining the edifice is strongly advised should intense rains occur during eruptive unrest. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft," PHIVOLCS added.
(Info courtesy: DOST-PHIVOLCS)
