By Dominique Gabriel G. Bañaga

The Philippine Institute of Volcanology and Seismology (Phivolcs) monitored a sudden increase in volcanic gas emitted by the Kanlaon volcano on Negros Island.

Based on an advisory yesterday morning, Phivolcs reported that the sulfur dioxide (SO2) gas emissions of the volcano have increased to an average of 1,099 tonnes per day, the highest recorded this year.

This is higher than the normal average of 124 tonnes per day logged in March of this year.

According to the United States Geological Survey, a sudden increase in SO2 emissions means that the volcano’s magma is relatively near the surface.

From April 1 to 30, the Phivolcs recorded 141 volcanic earthquakes at the Kanlaon, which averaged five per day.

Volcanologists from Phivolcs explained that the earthquakes occur at shallow depths, roughly 10 kilometers from the surface and run across the northern to western portions of the volcano.

Ground deformation data also showed short-term inflation of the lower and middle slopes since March of this year, indicating slow pressurization within the volcano.

Despite the sudden increased activity, Phivolcs said in its advisory that Kanlaon remains under Alert Level 1 status, which means residents are prohibited from entering the volcano’s four-kilometer permanent danger zone.

The agency also told the Civil Aviation Authority of the Philippines to advise pilots to avoid flying close to the volcano’s summit as any ejecta from a sudden phreatic eruption is hazardous to aircraft.

Kanlaon is the highest point in the Visayas with an elevation of 2,465 meters.

The volcano last erupted in December of 2017, and has been under Alert Level 1 status since 2020./DGB, WDJ