LGUs should check 'lingering hazards' first before letting residents go back: Phivolcs

ABS-CBN News

Posted at Jan 20 2020 10:24 PM | Updated as of Jan 20 2020 11:46 PM

Fishermen in Laurel, Batangas continue to raise and harvest tilapia, saying it's their only livelihood, on January 20, 2020, more than a week after Taal Volcano's phreatic eruption last January 12. Batangas Governor Hermilando Mandanas recently directed town mayors to cancel 'window hours' which allow evacuees to check on their homes and livestock amid a possible "hazardous explosive eruption" that may happen within hours or days. Mark Demayo, ABS-CBN News

MANILA - Local government officials should ensure there are no lingering hazards in their areas of responsibilities before allowing evacuees to go back, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Monday.

Phivolcs Director Renato Solidum said local governments should reevaluate the situation in their areas as part of the standard procedure during disasters and calamities.

"As guidance, in any disaster, when the threat is over, whether it's a tsunami or earthquakes, or volcanic eruptions or other related hazards, the local government must ensure that when people can go back, at some point after the threat has passed, we have to check if there are lingering hazards in the area," he explained.

"For example, currently, we have fissures on the ground. It's still moving, and it's affecting houses. So they need some time to reevaluate the situation before they would order the people to go back. That's the standard procedure," Solidum added.

He also said volcanic eruptions, unlike typhoons or earthquakes, usually have lingering hazards like ashfall.

"Baka malimutan natin na porke, kunyari lang, na walang threat, puwede nang bumalik ang mga tao, hindi puwedeng ganoon, kasi may mga hazards pa....Hindi yan bagyo na pagdaan, tapos na. 'Pag lindol eh tapos na, although may mga aftershocks," Solidum said.

"But just to give you a sense of other hazards that need to be considered, may ashfall na sa mga wall na matatarik dahil doon sa wall from Tagaytay down to the lake shore, at may mga abo 'yan. May abo. So 'pag umulan nang malakas, puwedeng maanod 'yung mga abo at mas maging erosive. So magkakaroon ng mga sediments na bababa. 'Yun din ang kailangang bantayan at ma-prevent na maapektuhan 'yung mga tao," he added.

Solidum's statement comes after the vice mayor of Talisay, Batangas appealed to President Rodrigo Duterte Monday to allow his constituents to return home even as state seismologists warned that a hazardous Taal Volcano eruption is still possible.

Speaking to radio DZMM, Talisay Vice Mayor Charlie Natanauan also criticized Solidum over the volcano alert warnings, saying the head seismologist should change his "opinion" about Taal's activity.

"Masyado niyang ano e, sabi niya mas malakas ang puputok na susunod, nag iipon lamang. Opinyon niya 'yon...Nag-iisa siya (Solidum) sa kaniyang opinyon. Kami buong Batangas ang naapektuhan sa kaniyang sinasabi. Pag-aralan niyang mabuti," Natanauan said.

(He is the only one saying that and it's affecting the whole Batangas province. He should study it well.)

In previous media briefings, Phivolcs warned the public about base surges or high-speed blasts of hot gas, ash and volcanic debris that can float over water and reach lakeshore communities. This is what happened during the deadly 1754 and 1965 eruptions of Taal, which killed 1,300 and 200 people, respectively. Base surges are not only deadly, killing everything on its path, they are also subsonic in speed, which means people cannot outrun them.

Phivolcs also said, despite observations of a calm Taal volcano in recent days, with only a steady steam emission and “infrequent weak explosions” that generated ash plumes as high at 500 to 100 meters, volcanic activities underground show otherwise. 

Alert level 4 remains up in Taal Volcano, which means a hazardous explosive eruption can happen within hours or days.