Taal records 185 volcanic quakes in last 24 hours

MANILA – Restive Taal Volcano has a total of 185 volcanic earthquakes recorded in the past 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Monday.

The figure includes seven low-frequency volcanic quakes, 176 volcanic tremors that lasted 1 to 16 minutes, and a low-level background tremor that has persisted since July 7.

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

Taal also continues to generate high levels of sulfur dioxide (SO2) gas emissions, with an average of 6,421 tonnes/day on July 11.

Steam-rich plumes reached 1,500 meters in height. The SO2 emission, however, is lower than the average 22,628 tonnes/day last July 4, which was the highest ever recorded in Taal.

Health authorities warned that prolonged exposure to SO2 may cause sore throat and difficulty in breathing.

Taal Volcano has been under Alert Level 3 (magmatic unrest) since July 1, which means that there is magmatic intrusion at its main crater that may further drive succeeding eruptions.

Phivolcs reiterated that the whole Taal Volcano Island is a permanent danger zone, and that entry into the TVI and the high-risk barangays of Agoncillo and Laurel must be prohibited due to the hazards of pyroclastic density currents and volcanic tsunami should strong eruptions occur.

It added that all activities on Taal Lake should not be allowed.

Communities around the Taal Lake shores should take precautionary measures against possible airborne ash and volcanic smog (vog) and calmly prepare for possible evacuation should unrest intensify, Phivolcs said.

Vog is a type of air pollution caused by volcanoes. It consists of fine droplets containing volcanic gas such as SO2 which is acidic and can cause irritation of the eyes, throat, and respiratory tract in severities depending on the gas concentrations and durations of exposure.