If there is an imminent explosion in Taal Volcano, it could be less powerful than the eruption in 2020 as magma has been already “depressurized,” according to Philippine Institute of Volcanology and Seismology (Phivolcs) chief science research specialist Ma. Antonia Bornas.
Despite this, Bornas advised the public to remain alert against possible volcanic hazards, such as base surges, volcanic tsunami, and ashfall in case an eruption occurs.
“Malamang ay hindi [na maulit ang 2020 eruption], sapagkat mababaw at na-depressurize na ang magma, patuloy itong sumisingaw ng volcanic gas, nawawalan ng gas overpressures, at ito ay nauuwi sa kawalan ng pwersa ng magma. (It is unlikely to have a repeat of the 2020 eruption because the magma had been shallow and depressurized, and continues to evaporate volcanic gas and lose gas overpressures, causing the magma to lose pressure),” Bornas explained during the Phivolcs,”Infobit: Usapang Bulkang Taal” virtual event on Wednesday, March 31.
Unlike the current volcanic activity, Bornas said that magma came from a deep-seated chamber within the Taal Volcano in the January 2020 eruption.
“Ito (2020 eruption) ay highly pressurized at mayaman sa volcanic gas na nagdulot ng mabilis at malakas na pagputok. (The 2020 eruption was highly pressurized and rich in volcanic gas that caused fast and powerful explosion),” Bornas pointed out.
Taal Volcano has been under Alert Level 2 since March 9, 2021 due to “elevated” unrest.
So far, the restive volcano in Batangas has registered 3,843 volcanic earthquakes from Feb. 13 to March 31, 2021.
Based on the Taal Volcano’s current activity, Bornas said there is a possibility of the occurrence of phreatic or steam-driven eruption; phreatomagmatic or Strombolian eruption; or minor ash or gas eruption.
“Kung maganap ang phreatomagmatic eruption, ang volcanic hazards na maaaring mangyari ay ang base surges tulad noong 1966 kung saan 300 na katao ang namatay dahil sa displacement ng tubig sa paligid ng lawa. Maaari ding magkaroon ng volcanic tsunami at pinong ashfall. (If a phreatomagmatic eruption occurs, the volcanic hazards that can occur are base surges, such as in 1966 where 300 people died due to water displacement around the lake. There can also be volcanic tsunamis and fine ashfall,” Bornas explained.
“Kung maganap ang Strombolian eruption, maaaring magdulot ng lava flow at spatter [pitak ng lava na naitsa] sa Taal Volcano Island, at magaspang na ashfall. (If a Strombolian eruption occurs, it can cause lava flow and spatter or chunk of lava in the Taal Volcano Island, and coarse ashfall),” she added.
Bornas also said that possible Taal eruption may originate in the main crater or in the flank vents of the Taal Volcano Island–off Calauit, Pira-piraso, Binintiang Malaki, Mt. Tabaro, or Binintiang Munti.
She reiterated that the public is prohibited from entering the volcano island, which is a permanent danger zone, especially the vicinities of the main crater and Daang Kastila fissure.
Occupancy and boating on Taal Lake is also strictly prohibited, Bornas said.