Mayon nears explosive phase, warns Phivolcs
LIGAO CITY—A record surge in sulfur dioxide (SO2) emissions from Mayon Volcano has raised the possibility of a more explosive eruption, the Philippine Institute of Volcanology and Seismology (Phivolcs) warned on Saturday.
Mayon emitted an average of 13,128 metric tons of volcanic SO2 per day on July 11, based on campaign ultraviolet spectrometry measurements conducted by Phivolcs.
The agency said the emission rate was the highest recorded from the volcano in the past 26 years and only slightly below the levels observed during Mayon’s explosive eruption in 2000.
Mayon has remained under Alert Level 3 and has been erupting continuously for 187 days.
Phivolcs said the spike in SO2 emissions coincided with heightened volcanic activity, including 97 low-frequency volcanic earthquakes associated with volcanic degassing and minor Strombolian activity at the summit crater, as well as 304 rockfall events caused by the collapse of new lava flows as of 8 p.m. on Saturday.
Inflation of edifice
Despite the increase in activity, the agency said only slight inflation of the volcanic edifice and a modest rise in overall seismic energy had been detected, conditions that remain consistent with the effusive eruption that has characterized Mayon since the onset of its 2026 unrest.
However, Phivolcs warned that the exceptionally high SO2 emissions may signal a change in eruptive behavior and could “even lead to an explosive eruption.”
Such an eruption, the agency said, could generate larger and farther-reaching pyroclastic density currents on all sectors of the volcano, hurl ballistic rock fragments from the summit crater and produce more widespread ashfall.
The potential impacts, it added, could be aggravated by prevailing adverse weather conditions.
