Threats from pyroclastic density currents and volcanic tsunami still loom over the 14-kilometer radius from the main crater of Taal Volcano despite its seemingly calmer activity on Wednesday morning.
Philippine Institute of Volcanology and Seismology (PHIVOLCS) resident volcanologist and Taal Volcano Observatory officer-in-charge Paolo Reniva warned of a possible base surge that could instantly destroy properties and kill people along shoreline communities near the volcano island, should a hazardous eruption occur.
"Ito ay posibleng mangyari kapag itinaas na natin sa Alert Level 5 ang status ng Taal. Ang base surge po 'yung pyroclastic flow na tatawid ng Taal Lake," Reniva said in an interview on Unang Balita.
"Masyado po itong mabilis, kung mapapansin ninyo ito ay 80 kilometers per hour. Ang distance natin sa volcano island is around seven to 10 kilometers lang so within minutes po puwede nang magkaroon ng impact 'yun sa mga ari-arian at sa mga tao po na malapit sa shoreline," he added.
Reniva said the pyroclastic materials that may be ejected by Taal Volcano can burn as these contain hot gases and ashes.
According to the United States Geological Survey, base surge is a "ring-shaped cloud of gas and suspended solid debris that moves radially outward at high velocity from the base of a vertical eruption column."
Meanwhile, volcanic tsunami may also be generated by a large eruption from Taal Volcano.
"Halimbawa sa isang malakas na pagsabog, may collapse po sa isang bahagi ng bulkan o epekto ng malakas na pagsabog na 'yun ay ma-displace ang tubig at tumawid papuntang shorelines," Reniva said.
The towns of Laurel and Agoncillo in Batangas are vulnerable to the said hazards as these have been previously affected by base surge and volcanic tsunami when Taal erupted in 1965.
Alert Level 4 remains over Taal Volcano, meaning a hazardous eruption is possible within hours to days.
President Rodrigo Duterte on Tuesday expressed satisfaction with the response of government agencies to the effects of the eruption of Taal Volcano.
Duterte said national and local government personnel in charge of disaster response must stay in affected areas “for a while until such time we are ready to declare that the crisis is over.”
The number of individuals displaced by the Taal Volcano eruption has reached 53,019, the National Disaster Risk Reduction and Management Council said Wednesday.
In its 6 a.m. situation report, the NDRRMC said the number is from 12,486 families in Batangas and Cavite. Of that number, a total of 10,000 families or 43,681 individuals are being assisted in 217 evacuation centers.
The NDRRMC also said more than P2 million worth of assistance was given to residents affected by the volcano's eruption.
Soldiers and rescuers on Wednesday morning were being readied to scour areas in Talisay town fronting the northern part of Taal Volcano Island for residents still refusing to heed to mandatory evacuation calls. —Dona Magsino/LBG/KG, GMA News