MANILA, Philippines — A volcanic tsunami is possible if the Taal Volcano alert level is raised to 5—when a hazardous eruption is in progress—the Philippine Institute of Volcanology and Seismology said Monday.
Winchelle Sevilla, Phivolcs supervising science research specialist, said there could be a volcanic tsunami if Taal’s activity further intensifies to Level 5.
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The restive volcano in Batangas remains under Alert Level 4, which means that “hazardous explosive eruption is possible within hours to days.”
Antonia Borjas, Phivolcs chief science research specialist, said the possible volcanic tsunami will only threaten areas around the Taal Lake.
“These are shorter period waves and the mechanism of generation is volcanic, not earthquake,” Borjas explained.
According to the country’s seismology agency, volcanic tsunami “occurs in caldera lakes when water is displaced by deformation of the lake floor caused by rising magma or entry of pyroclastic density current or landslides into the lake, or in seas when water is displaced by PDCs or debris avalanches from volcanoes.”
Volcanic tsunamis differ from those generated by large magnitude offshore earthquakes, which are long-period waves generated by fault displacement or deformation of the seafloor.
A magmatic eruption was recorded in Taal Volcano from 2:49 a.m. to 4:28 a.m. A magmatic eruption is characterized by weak lava fountain accompanied by thunder and flashes of lightning.
Alert Level 5 would come with an eruption column of up to 15 kilometers high and could bring a base surge, which Phivolcs describes as thick smoke and ash that could travel across the surface of Taal Lake.
Taal’s last eruption was in 1977.