MANILA, July 8 (Mabuhay) — Restive Taal Volcano has generated a total of six phreatomagmatic bursts and 60 volcanic earthquakes for the past 24 hours.
In its latest bulletin Thursday, the Philippine Institute of Volcanology and Seismology (Phivolcs) said the last phreatomagmatic burst was observed at 9:41 p.m. Wednesday, producing a short jetted plume up to 700 meters high.
Phivolcs’ earlier data bared that phreatomagmatic explosions were recorded at 5:18 a.m., 8:46 a.m., 9:15 a.m., 9:26 a.m., and 11:56 a.m. These phreatomagmatic eruptions lasted from one to seven minutes.
“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 director Renato Solidum, Jr. said.
He added that small phreatomagmatic eruption, together with the continued emission of high amounts of sulfur dioxide (SO2) and the increasing number of earthquakes indicate a continued magmatic activity that may lead to larger explosions or phreatomagmatic eruptions.
Sixty volcanic quakes are caused by movements or eruptions of magma from the volcano. The figure includes five explosion-type earthquakes, 24 low-frequency volcanic earthquakes, 21 volcanic tremor events having durations of two to four minutes, 10 hybrid earthquakes, and low-level background tremors that eased at 06:21 p.m. but resumed at 09:52 p.m.
Hybrid earthquakes indicate rock fracturing and magma or fluid movement.
High levels of SO2 gas emissions averaging at 11,397 tonnes/day, and steam-rich plumes that rose 1,500 meters high were also recorded.
Taal Volcano has been under Alert Level 3 (magmatic unrest) since July 1 after Phivolcs recorded a short-lived dark phreatomagmatic plume 1 kilometer-high in the afternoon.
Phivolcs reminded the public that under this level, magma extruding from the main crater could drive explosive eruption.
Entry into Taal Volcano Island (TVI) and into 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 said.
Last July 1, Phivolcs recommended complete evacuation in the TVI, Taal Lake, Agoncillo, Batangas (Banyaga, Bilibinwang), and Laurel, Batangas (Gulod, Boso-Boso, Lakeshore Bugaan East). (MNS)