Taal Volcano in Batangas recorded a sharp decline in sulfur dioxide emissions and an increase in volcanic earthquakes over the past 24 hours.
The information comes from the Philippine Institute of Volcanology and Seismology (Phivolcs).
In its Saturday morning (Oct. 31) bulletin, Phivolcs reported sulfur dioxide emissions of 217 metric tons during the latest observation period.
This volume is down from the daily average of 424 metric tons recorded from Oct. 28 to 30.
The gas plume rose 500 meters above the main crater and drifted southwest.
Despite the decline in sulfur dioxide emissions, the volcano’s seismic activity intensified, with Phivolcs recording 23 volcanic earthquakes during the 24-hour monitoring period, up from 10 the previous day.
The volcano recorded seismic activity on most days this month, peaking at 43 volcanic earthquakes on Oct. 19.
No volcanic earthquakes or tremors were detected on Oct. 1, 3, 4, 5 and 7.
The continued seismic activity follows a series of phreatic and phreatomagmatic eruptions observed at Taal Volcano this month.
Phivolcs reported two phreatic, or steam-driven, eruptions on Oct. 19 and another on Oct. 20. Another phreatic eruption was recorded on Oct. 21.
The agency also reported about a phreatomagmatic eruption on Oct. 8, two more on Oct. 21, and another on Oct. 22.
There was no upwelling of hot volcanic fluids in the Main Crater Lake and no volcanic smog, or vog, during the latest monitoring period.
Alert Level 1 remains in effect over Taal Volcano, indicating continued low-level unrest. Sudden steam-driven or phreatic eruptions, volcanic earthquakes, minor ashfalls and hazardous volcanic gas emissions remain possible, Phivolcs warned.