TAAL Volcano in Batangas had three phreatic or steam-drive eruptions on Sunday, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported yesterday.

The volcano remains under Alert Level No. 1 (low-level unrest) despite the “small phreatic eruptions” which Phivolcs said lasted for one to three minutes.

Phivolcs defines phreatic eruptions as “steam-driven explosions that occur when water beneath the ground or on the surface is heated by magma, lava, hot rocks, or new volcanic deposits.”

Phivolcs said it recorded one volcanic tremor, which lasted for 10 minutes, also on Sunday. Six volcanic tremors were recorded the previous day.

The volcano’s sulfur dioxide emission was measured at 8,927 tons last Saturday. This produced a 1,200-meter tall plume that drifted northeast, southwest, and north-northeast.

Phivolcs said there was a long-term deflation of the Taal caldera and short-term inflation of the general northern and southeastern flanks of the Taal Volcano Island.

Phreatic explosions are among the possible hazards under Alert Level 1. The others are volcanic earthquakes, minor ashfall, lethal accumulations or expulsions of volcanic gas.

Phivolcs continues to advise against entry to the Taal Volcano Island which is classified as a permanent danger zone.

It is also discouraging aircraft flights close to the volcano.