PHOTO COURTESY OF SHIELA TAN
LUCENA CITY 鈥� At least 12 volcanic earthquakes in Taal Volcano in Batangas province were detected over the last 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported on Friday morning, Sept. 20.
On Thursday, the earthquakes were accompanied by eight volcanic tremors, Phivolcs said in its bulletin.
On Wednesday, the volcano recorded three volcanic earthquakes and one tremor lasting two minutes.
READ: 鈥榁og鈥� reappears after Taal Volcano emits voluminous sulfur dioxide
Phivolcs defines volcanic earthquakes as those 鈥済enerated by magmatic processes or magma-related processes beneath or near an active volcano.鈥�
鈥淯nlike tectonic earthquakes that are produced by faulting, volcanic earthquakes are directly produced by many processes and are therefore much more varied in characteristics,鈥� the agency explained.
Volcanic tremors, on the other hand, are 鈥渃ontinuous seismic signals with regular or irregular oscillations and low frequencies (typically 0.5鈥�5 Hz) that can last for more than a minute.鈥�
The Phivolcs added: 鈥淭remor 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.鈥�
In its latest update, Phivolcs also recorded the emission of 8,223 metric tons (MT) of sulfur dioxide (SO2) from Taal鈥檚 main crater, which rose 1,200 meters high before drifting in a north-northeast direction.
An 鈥渦pwelling of hot volcanic fluids in the Main Crater Lake鈥� was also observed on Taal Volcano Island, locally known as 鈥淧ulo,鈥� which sits in the middle of Taal Lake.
The Phivolcs reported the absence of 鈥渧og,鈥� or volcanic smog, during the latest observation period.
Taal Volcano is still under alert level 1 (low level of volcanic unrest), Phivolcs said.
The agency reminded the public that Taal Volcano remained in an
鈥渁bnormal condition鈥� and 鈥渟hould not be interpreted to have ceased unrest nor ceased the threat of eruptive activity.鈥� INQ