• CHERYL G. CRUZ
The Philippine Institute of Volcanology and Seismology logged another 15 volcanic earthquakes at Mount Kanlaon in Negros Island Nov. 23, and reminded residents and tourists that entry into the four-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited.
“Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ejecta from any sudden phreatic eruption can be hazardous to aircraft,” the Phivolcs said in an advisory.
On Nov. 22, Phivolcs also said it logged “increased seismic activity at Kanlaon Volcano” with 15 volcano-tectonic (VT) earthquakes recorded by the Kanlaon Volcano Network between 3:58 a.m. and 5 a.m. Wednesday…beneath the northern flank of the Kanlaon range”.
It said that volcanic sulfur dioxide (SO2) gas emission from the summit crater has been elevated since May 1, 2023, averaging 570 tonnes a day.
The SO2 measurement Nov. 22 was at 1,334 tonnes. “Ground deformation data from continuous GPS and electronic tilt measurements have been recording shorter-term inflation of the southwestern middle slopes since October 2023 and longer-term inflation of the entire edifice since March 2022”.
While monitoring parameters in the past months have been consistent with shallow hydrothermal activity driven by degassing of deeper magma, ongoing VT earthquake activity indicates shallow rock-fracturing on the edifice, which may lead to further unrest, the advisory stressed.
Phivolcs said that Alert Level 1 prevails over Kanlaon. “Should the uptrend in monitoring parameters persist, the volcano status may be raised to Alert Level 2 to warn of increasing unrest”. | CGC
