Phivolcs detects rise in Taal Volcano gas emission
A map created by the Philippine Institute of Volcanology and Seismology shows the location of 12 volcanic quakes, marked with red dots, recorded at Taal Volcano in the past 24 hours on May 28, 2025. The paler dots are the locations of quakes in the past two weeks. — Photo from Phivolcs/Facebook
LUCENA CITY — Taal Volcano in Batangas province has continuously increased sulfur dioxide emissions in the past days.
The Philippine Institute of Volcanology and Seismology (Phivolcs) reported on Wednesday, May 28, that during the past 24-hour observation period, the volcano emitted 6,289 metric tons (MT) of sulfur dioxide, with plumes reaching 900 meters high that drifted northwest.
On May 26, Taal Volcano emitted 5,418 MT of toxic gas.
On May 21, the volcano released 2,285 MT of sulfur dioxide, which increased to 4,049 MT the next day. However, the emission level dropped to 3,237 MT on May 23 and then rose again to 4,261 MT the next day, remaining at that level until May 25.
However, there were no reports of upwelling hot volcanic fluids in the main crater lake of Taal Volcano Island, which sits in the middle of Taal Lake.
READ: Taal Volcano sees surge in seismic activity
No volcanic smog or “vog” was also observed during the monitoring periods.
Taal Volcano also recorded 12 volcanic earthquakes and 9 volcanic tremors that lasted two to seven minutes during the latest observation period.
Phivolcs defines volcanic earthquakes as those “generated by magmatic processes or magma-related processes beneath or near an active volcano.”
“Unlike tectonic earthquakes that are produced by faulting, volcanic earthquakes are directly produced by many processes and are therefore much more varied in characteristics,” the agency explained.
Volcanic tremors, on the other hand, are “continuous seismic signals with regular or irregular oscillations and low frequencies (typically 0.5–5 Hertz) that can last for more than a minute.”
Taal Volcano is still under Alert Level 1 (low level of volcanic unrest), Phivolcs said.
The agency reminded the public that Taal Volcano remained in an “abnormal condition” and “should not be interpreted to have ceased unrest nor ceased the threat of eruptive activity.” /das
