MANILA-Three phreatomagmatic eruptions occurred in Taal Volcano on Thursday, Philippine Institute of Volcanology and Seismology (Phivolcs) Director Renato Solidum Jr. said.

These occurred at 10:39 a.m. for two minutes; 10:47 a.m. and 10:55 a.m., both for one minute.

Solidum told the Philippine News Agency that the first eruption generated plumes 900 meters high, and the two others both generated plumes 500 meters tall.

Phreatomagmatic eruptions are caused by the interaction of magma and water. Eruptions normally consist of multiple explosive events, the interval of which may vary.

Phivolcs reported that for the past 24 hours, no volcanic earthquake caused by movements or eruptions of magma from the volcano was detected. However, low-level background tremor has persisted since March 29.

Solidum earlier said a low-level background tremor may signify stronger hydrothermal activity or boiling of groundwater, and degassing of the volcano.

Upwelling of hot volcanic fluids in the main crater lake generated plumes 1,500 meters high. Sulfur dioxide (SO2) emission averaged 6,405 tons on Wednesday, according to Phivolcs.

Alert Level 3 (magmatic unrest) is maintained over the Taal Volcano, indicating there is magmatic intrusion at the main crater that may further drive succeeding eruptions.

Magmatic intrusion refers to the rise of magma into shallower levels of the volcano, which can cause further explosions as the magma can explode because of gases inside it or when the magma interacts with groundwater in the shallower levels of the volcano.

Phivolcs has recommended the evacuation from Taal Volcano Island (TVI) and high-risk barangays of Bilibinwang and Banyaga in Agoncillo and Boso-Boso, Gulod and eastern Bugaan East in Laurel, Batangas due to the possible hazards of pyroclastic density currents and volcanic tsunami should stronger eruptions subsequently occur.

It also reiterated that entry into TVI and these barangays in Agoncillo and Laurel must be prohibited, and all activities on Taal Lake should not be allowed. (PNA)