Legazpi: A significant increase in sulfur dioxide (SO2) gas emission was observed in Mayon Volcano recently, but raising the volcano's alert status is unlikely for now, Philippine Institute of Volcanology and Seismology (Phivolcs) Director Teresito Bacolcol said on Friday.

According to Philippines News Agency, Bacolcol mentioned that natural fluctuations in SO2 emissions are expected and normal over several days. However, he noted that the current trend is significant, with elevated SO2 emissions sustained over several days. Phivolcs recorded 7,115 tonnes of SO2 emission on August 31, escalating to 8,165 tonnes on September 3.

Bacolcol elaborated on the factors influencing these fluctuations, highlighting the role of pressure, magma ascent, and gas passage toward the surface. He noted that Mayon Volcano's background SO2 level at Alert Level 0 is typically around 500 tonnes per day or even lower.

"In comparison, emissions reached 7,115 tonnes per day on August 31 and 8,165 tonnes per day on September 3, significantly above the normal background level," Bacolcol remarked. He emphasized that the elevated SO2 emissions indicate a substantial volume of gas emanating from the volcano.

While there exists a possibility of elevating Mayon Volcano's alert level, Bacolcol clarified that SO2 levels alone are not the sole determinant. "We are also looking at the number of earthquakes, increase in mass flux (more pyroclastic density currents or uson, longer lava flows, more rockfalls), ground deformation, and other parameters," he explained.

At present, Alert Level 2 remains deemed appropriate, though Bacolcol assured that Phivolcs is diligently monitoring Mayon Volcano. The public is reminded of the ongoing volcanic unrest, and entry into the six-kilometer permanent danger zone is strictly prohibited.

"Also with the ongoing habagat (southwest monsoon), the public, especially those residing in nearby river channels, should take precautions against lahar," Bacolcol advised.