Increased sulfur dioxide emissions detected at Mayon Volcano
The Philippine Institute of Volcanology and Seismology has observed an increase in volcanic sulfur dioxide emissions from Mayon Volcano, even as other signs of activity show a temporary decline.
In an advisory issued at 10:30 p.m. on Friday, PHIVOLCS noted that while rockfall and pyroclastic density current activity have decreased—indicating a slowdown in lava effusion from the summit crater—SO2 emissions have "significantly increased."
"Volcanic SO2 flux yesterday averaged 4,569 tonnes/day and increased today, 10 July 2026, to 7,475 tonnes/day, the highest emission from Mayon recorded in the last 16 years," the agency stated.
For comparison, SO2 emissions have averaged 2,300 tonnes/day since the current eruption began on Jan. 6.
PHIVOLCS warned that the rising gas emissions likely foreshadow further eruptive activity at the summit. These hazards could be worsened by poor weather conditions.
Now in its 186th consecutive day of "eruptive unrest," Mayon remains under Alert Level 3.
"This could generate volcanic hazards including lava flows and collapse-fed rockfall and PDCs or uson on the southern and eastern slopes as well as ashfall that could be dispersed extensively by strong winds," they said.
They advised the public to refrain from entering the 6-kilometer radius Permanent Danger Zone due to the danger posed by these and other volcanic hazards.
Increased vigilance and pre-emptive response actions to guard against lahars and sediment-laden streamflow along channels draining the edifice are also advised as prolonged heavy rains over Albay Province could occur with the passage of Typhoon “Inday” east of Luzon.
"Civil aviation authorities should continue to advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft," they said.
"DOST-PHIVOLCS maintains close monitoring of Mayon Volcano and any new development will be communicated to all concerned stakeholders," they continued.
Mayon Volcano remains at Alert Level 3 following the July 11 7 a.m. update from PHIVOLCS.
According to Centers for Disease Control and Prevention, inhaling sulfur dioxide causes irritation to the nose, eyes, throat, and lungs. It can also aggravate chronic pulmonary diseases, such as asthma and emphysema.
