‘Worst case scenario:’ Manila Trench Segment 2 movement may generate magnitude 8.4 quake

Metro Manila, Philippines - A magnitude 8.4 earthquake is the “worst case scenario” amid the tremors in the Manila Trench, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

Phivolcs, in a tsunami simulation, divided the Manila Trench into four segments.

“Ang mga sequence ng offshore earthquakes sa Santa Catalina, Ilocos Sur ay nangyayari sa Manila Trench segment 2 (MT2),” Phivolcs said in a statement on Monday night, Dec. 23.

[Translation: The sequences of offshore earthquakes in Santa Catalina, Ilocos Sur occur in Manila Trench Segment 2.]

“Base sa model, ang worst case scenario kung sakaling gumalaw ang buong MT2 ay isang Magnitude 8.4 na lindol,” it added.

[Translation: Based on the model, the worst case scenario should the whole MT2 move is a magnitude 8.4 quake.]

Should the tremor generate a tsunami, Phivolcs said the first wave – with a height of up to 15 meters – would reach the coasts of Zambales, Pangasinan, La Union, Ilocos Sur, Ilocos Norte, and Cagayan within two to 15 minutes.

Phivolcs advised the public to be on alert for signs of a tsunami: a strong quake, sudden change in water level, and peculiar sound from the sea. If one of the signs is present, people should evacuate and move to higher grounds or away from the sea.