Sulfur emissions from Mayon Volcano have surged to more than twice their average level since Aug. 5, prompting the Philippine Institute of Volcanology and Seismology (Phivolcs) to warn of possible renewed eruptive activity.
In its bulletin on Tuesday, Sept. 1, the agency said Mayon released 7,115 tons of sulfur dioxide on Aug. 31, the second-highest emission recorded since volcanic gas concentrations began declining on July 16.
Since Mayon was placed under Alert Level 2, or moderate unrest, on Aug. 5, its sulfur emissions have averaged 3,844 tons a day, Phivolcs said.
The surge in gas emissions coincided with a slight increase in low-frequency volcanic earthquakes, with 12 recorded as of midnight Tuesday. Phivolcs attributed the earthquakes to volcanic degassing, while real-time seismic energy release remained at background levels.
The agency also detected short-term swelling or pressurization in Mayon’s northern and eastern flanks based on electronic tilt monitoring.
‘Elevated volcanic sulfur dioxide emissions could forewarn of a potential shift to renewed eruptive activity at the summit crater,’ it said.
A renewed eruption could generate pyroclastic density currents or uson, rockfall, ballistic fragments, and widespread ashfall, it added.
Phivolcs said Mayon remained under Alert Level 2 but urged residents and local governments to prepare for a possible escalation to Alert Level 3, particularly those in areas vulnerable to pyroclastic density currents.
It reiterated that entry into the six-kilometerPermanent Danger Zone is prohibited and warned of possible lahars and sediment-laden streamflows along channels draining Mayon, particularly during prolonged heavy rains or a simultaneous explosive eruption.
Pilots were also advised to avoid flying near the summit, as ash and ballistic fragments from a sudden eruption could endanger aircraft