THE Philippine Institute of Volcanology and Seismology (Phivolcs) has warned residents of Davao Region against a possible strong earthquake to hit the province that may originate from Davao Oriental and Compostela Valley.
Phivolcs research specialist Desiderio Cabanlit, in Friday's Kapihan sa PIA forum at NCCC Mall Davao, said based on their recent study, Mati and Compostela areas are possible active fault lines that may move.
"Part of the Mindanao fault zone is Surigao City down to Mati City in Davao Oriental with a total length of 320 kilometers. Yung segment ng Mati at tsaka yung segment ng Compostela, yun ang posibleng gagalaw sa ating region," Cabanlit said.
He said based on their data, it was in 1893 when a 7.2-magnitude earthquake struck Monkayo in Compostela Valley, which may also recur anytime.
He said strong earthquakes can happen again in the same area.
"Mubalik ug usab ilabi na kung kusog siya (It may happen again especially if it's strong)," Cabanlit said.
He added that when it could happen, Davao area would feel a "7.0 to 7.1 magnitude and ground shaking could reach Davao in less than one minute."
He said types of collateral hazards are ground shaking, ground rapture, tsunami, liquefaction and sinkholes, which may vary depending on the geographical and topographical location.
Cabanlit added a 7-magnitude earthquake may ruin a lot of buildings especially those that are 50 to 60 years old.
Another possible occurrence of earthquake would be in Philippine Trench in Governor Generoso in Davao Oriental, which was also hit by an 8.3 magnitude earthquake on April 15, 1924. When this happens again, it could affect Davao with an 8.0 magnitude and can also cause tsunamis.
He said that in his simulation, once earthquake would hit Gov. Generoso with the same magnitude, it can cause very serious damage.
"Ang iyang tsunami height muabot ug mga four meters, pagbagsak sa balud ang iyang inundation ang inland attack bitaw niya, muabot siyag halos isa ka kilometro. Simulation lang ni siya ha wala ko nag-ingon na mao ni mahitabo (The tsunami height would reach four meters and the fall of the waves, it's inundation or its inland attack would reach almost one kilometer. It's just a simulation, I didn't say that will exactly happen)," Cabanlit said.
He also said an official report has yet to be released on the two active faults that were discovered in Davao.