A QUIET emission of steam plume has been monitored at Taal Volcano’s main crater, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Friday.

This began intermittently at 11 p.m. on Thursday with the onset of rains, Phivolcs said on its Facebook page.

Activity at the main crater consisted of the upwelling of hot volcanic fluids in its lake and this is generating a voluminous steam plume 2 km. high, drifting southwest, Phivolcs said in its bulletin.

No volcanic earthquake or infrasound from Taal’s volcanic activity was recorded since 12:36 p.m. Thursday.

In the past 24 hours, 10 volcanic earthquakes, including two low-frequency volcanic quakes and eight volcanic tremor events that lasted eight to 37 minutes were recorded in Taal.

Volcanic earthquakes are caused by movements or eruptions of magma from the volcano, compared to tectonic quakes, which are caused by fault movements.

Volcanic quakes last less than a minute, while volcanic tremors last more than a minute, several minutes, hours, or even days.

Sulfur dioxide (SO2) emission averaged 3,051 tons per day on May 20.

Alert level 2 (increased unrest) is maintained over Taal.

Phivolcs Director Renato Solidum Jr. earlier said the varying number of volcanic quakes in Taal in the past days were due to the non-continuous magma and gas movement.

There were days when Phivolcs recorded a significantly high number of volcanic quakes and days with only a few earthquakes.

It reiterated that elevated unrest has been recurring and that volcano conditions remain unstable.

Sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within and around the Taal Volcano Island, Taal’s permanent danger zone.

Phivolcs reiterated that entry into the island, especially in the vicinities of the main crater and the Daang Kastila fissure, must be strictly prohibited. Philippine News Agency