(PNA file photo) MANILA - An increase in volcanic sulfur dioxide (S02) emission has been observed in the Taal Volcano, the Philippine Institute of Volcanology and Seismology (Phivolcs) on Wednesday said. A total of 12,125 tons of S02 gas was recorded on Wednesday, the highest since the volcano was placed under Alert Level 1 (low-level unrest) last July 11. This volcanic gas is expected to drift northeast of the Taal Volcano Island. In an advisory, Phivolcs said the increased degassing has been visible in the form of upwelling in the Main Crater Lake and voluminous steam-rich plume activity in the past three days. The average S02 emission since July 15 was 4,952 tons per day, higher than the 1,290 tons/day average between May and mid-July this year. Phivolcs said volcanic smog or vog has been observed since Tuesday over the western Taal Caldera, and reported to have been heavy over the town proper of Laurel and Barangay Banyaga in Agoncillo, where damage to vegetation was also documente