LUCENA CITY: Six volcanic earthquakes, accompanied by five volcanic tremors, were detected in Taal Volcano in Batangas province over the last 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported on Monday (Dec 9).
The volcanic tremors lasted four to five minutes, Phivolcs said in its bulletin.
On Sunday, state volcanologists also reported that the volcano logged five volcanic tremors and another five tremors on Saturday.
Phivolcs defines volcanic earthquakes as those “generated by magmatic processes or magma-related processes beneath or near an active volcano.”
“Unlike tectonic earthquakes that are produced by faulting, volcanic earthquakes are directly produced by many processes and are therefore much more varied in characteristics,” the agency explained.
Volcanic tremors, on the other hand, are “continuous seismic signals with regular or irregular oscillations and low frequencies (typically 0.5–5 Hz) that can last for more than a minute.”
The Phivolcs added: “Tremor can be caused by different processes inside the volcano, including resonance triggered by magma or magmatic gas flowing through cracks and vents, successive overlapping low-frequency earthquakes, and eruptions of magma.”
In its latest update, Phivolcs recorded the emission of 1,207 metric tonnes of sulfur dioxide from Taal’s main crater, which rose 600 metres high before drifting in the west-southwest direction.
The Phivolcs classified the latest spewing activity of the volcano as “weak emission.”
The agency reported no upwelling of hot volcanic fluids in the Main Crater Lake on Taal Volcano Island, locally known as “Pulo,” which sits in the middle of Taal Lake.
No volcanic smog, or “vog,” was observed during the latest monitoring period.
On Dec 3, the volcano experienced a minor phreatomagmatic eruption that lasted four minutes.
Phivolcs reminded the public that Taal Volcano is still under Alert Level 1, indicating that “low-level unrest” remained in effect.
It reiterated that entry into the volcano island’s main crater, the Daang Kastila fissure area, and the Mt Tabaro eruption site is prohibited. - Philippine Daily Inquirer/ANN
