LUCENA CITY, Quezon: Taal Volcano in Batangas showed a slight increase in sulfur dioxide (SO₂) emissions, while seismic activity remained generally low, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Friday (Jan 9).
In its 24-hour monitoring, Phivolcs reported that Taal emitted 150 metric tonnes of sulfur dioxide, which the agency classified as a “weak emission.”
The figure is slightly higher than the daily average of 78 metric tonnes recorded since Dec 31 last year.
Despite the increase in gas output, seismic activity remained minimal. Phivolcs recorded only three volcanic earthquakes during the monitoring period, noting further that no seismic events were detected the previous day.
However, on Jan 1, Phivolcs logged 51 volcanic earthquakes and 13 volcanic tremors. This was followed by a brief lull on Jan 2, when no seismic activity was recorded.
From Jan 3 to 7, the volcano registered a total of 363 volcanic earthquakes and 22 volcanic tremors, with the highest daily count reaching 55 earthquakes on Jan 4.
Monitoring data for December showed relatively calm conditions, when Phivolcs recorded a total of only 101 volcanic earthquakes and 26 tremor episodes.
Phivolcs explained that volcanic earthquakes are generated by magma-related processes beneath or near an active volcano.
Volcanic tremors, meanwhile, are continuous seismic signals with regular or irregular oscillations at low frequencies—typically between 0.5 and 5 hertz—and may last for more than a minute.
The agency also noted that no volcanic smog, or “vog,” and no upwelling of hot volcanic fluids in the main crater lake were observed during the monitoring period.
Phivolcs reiterated that Alert Level 1 remains in effect over Taal Volcano, indicating that it remains in an abnormal condition and that volcanic unrest has not ceased. - Philippine Daily Inquirer/ANN
