Kanlaon’s seismic activity increasing

BACOLOD CITY, Philippines — After spewing elevated levels of sulfur dioxide gas in the past few days, Kanlaon Volcano on Negros Island yesterday showed an increase in seismic activity, according to the Philippine Institute of Volcanology and Seismology.

Phivolcs said a total of 90 volcanic earthquakes were recorded by the Kanlaon Volcano Network between 3 p.m. on Tuesday and noon yesterday.

Most of the quakes occurred within 20 kilometers beneath the southeastern sector of the volcano’s edifice and consisted of five volcanic-tectonic and 85 weak low-frequency events.

The volcanic-tectonic events were produced by the fracturing of the rocks while the weak low-frequency indicated movement of volcanic fluids, Phivolcs said.

Kanlaon’s sulfur dioxide emissions remain elevated since it erupted on June 3, averaging 3,254 tons per day.

“On Tuesday, the average sulfur dioxide emission rose to 5,083 tons,” Phivolcs said, noting the normal figure is only 300 tons per day.

Ground deformation data from continuous GPS and electronic tilt measurements indicated an ongoing inflation of the edifice that started between April and July 2023, and a longer-term inflation since March 2022.

The data showed that a slow, sustained pressurization is happening inside the volcano. . – Romina Cabrera