Manila: The Philippine Institute of Volcanology and Seismology (Phivolcs) on Monday advised communities near Mayon and Kanlaon volcanoes to remain vigilant and adhere to official safety advisories as both volcanoes continue to show signs of activity, despite unchanged alert levels.
According to Philippines News Agency, Phivolcs Director Teresito Bacolcol, in a Bagong Pilipinas Ngayon interview, stated that Mayon and Kanlaon remain under Alert Levels 3 and 2, respectively, based on the latest monitoring data. This update follows Mayon's record high sulfur dioxide (SO2) emission in 26 years, with 13,928 tons per day noted on July 11. Bacolcol clarified reports that mistakenly referred to the highest emission level in 16 years.
Sulfur dioxide, a volcanic gas released by magma, is a key indicator of volcanic activity. However, Bacolcol emphasized that the agency considers multiple factors in its assessments. "We do not only look at SO2," he noted, citing lava effusion, volcanic earthquakes, rockfall activity, crater glow, and slight inflation on the northeastern flanks of Mayon as additional indicators of unrest. Despite a decrease in sulfur dioxide emissions to 5,842 tons per day on Sunday, levels remain higher than normal.
Earlier on Monday, Phivolcs observed a pyroclastic density current, known locally as "uson," on Mayon. Although this event was brief and reached only about 300 meters down the volcano's slope, Bacolcol warned against interpreting a slowing lava flow as a decrease in activity. He reiterated that magma beneath the volcano remains active and continues to release volcanic gas.
Over the past 24 hours, Phivolcs recorded weak Strombolian activity, with 92 volcanic earthquakes and 299 rockfall events, indicating ongoing volcanic activity. Bacolcol explained that this minor activity refers to short-lived bursts of lava, distinct from sustained lava fountaining.
Bacolcol also highlighted the health risks associated with elevated sulfur dioxide levels, which can irritate the eyes, nose, and throat, and exacerbate respiratory conditions. He advised residents to minimize outdoor activities when volcanic gas levels are high and to follow local government advisories.
Regarding Kanlaon, Bacolcol reported that the volcano remains under Alert Level 2 following its moderately explosive eruption on July 9, which affected 31 barangays across 12 municipalities and seven cities. Phivolcs recorded eight volcanic earthquakes, 741 tons per day of sulfur dioxide emissions, and continued ground inflation at Kanlaon over the past 24 hours. Bacolcol stated that the alert level would be raised only if data indicate a sustained increase in activity.
Residents were advised to handle volcanic ash with care, using protective gear and proper disposal methods to prevent blockages and flooding. Bacolcol urged calmness but emphasized the importance of vigilance, given the active state of both volcanoes. He reiterated the importance of adhering to recommended danger zones-four kilometers for Kanlaon and six kilometers for Mayon-and following advisories from Phivolcs and local government units.
