MANILA – Volcanic activity at Kanlaon Volcano in Negros Island may be pointing towards higher chances of a phreatic eruption, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Friday, June 9.
The volcano has been under Alert Level 1 since March 11, 2020 due to an increase in low-frequency volcanic earthquakes.
Based on its latest monitoring, Phivolcs has observed at least three volcanic earthquakes on June 9, with the volcano’s edifice inflated. On Monday, June 5, Kanlaon also emitted over 1,000 tons of sulfur dioxide.
While magmatic eruptions are still more dangerous compared to phreatic eruptions, the latter can still be worrisome, said Phivolcs Chief Science Research Specialist Maria Antonia Bornas.
“Ang problema sa phreatic eruption, maraming ganitong klaseng pagputok ang nagaganap ng walang precursory signals. Sa mga nakalipas na taon, pawang mas maraming pinapatay ang phreatic eruption kesa sa magmatic eruption,” Bornas said.
Bornas added that during Kanlaon’s phreatic eruption in 1996, three people were killed after being hit by volcanic debris.
Aside from phreatic eruption, state volcanologists are also not ruling out the possibility of other volcanic hazards.
“Matagal nang hindi nagkakaroon ng totoong magmatic eruption ang Kanlaon Volcano. Batay sa kaniyang geology, ito ay maaaring maglabas ng napakaraming lava flow. Pangalawa, pwede itong sumabog explosively. Pangatlo, pwede itong magkaroon ng flank eruption, ‘yung sa tagiliran, hindi natin mae-expect ‘yung mga ganiyan,” the Phivolcs official said.
Kanlaon also has a history of a debris avalanche, which makes an eruption dangerous. Unlike the Mayon and Taal volcanoes, a plume has not been observed over Kanlaon.
Nevertheless, state volcanologists advised against entry into Kanlaon’s four-kilometer radius permanent danger zone, as well as flying aircraft close to the volcano.
On Tuesday, June 6, the Civil Aviation Authority of the Philippines (CAAP) included Kanlaon Volcano as among the volcanoes that airmen should avoid flying in close proximity.
A Notice to Airmen (NOTAM) B1957/23 had been issued, advising flight operators to avoid flying in close proximity to Kanlaon Volcano’s summit due to the possibility of sudden and hazardous steam-driven or phreatic eruptions.
Such eruptions pose a significant hazard to aircraft from the surface up to 10,000 feet, it said. (ABS-CBN News)
