Phivolcs: Strong quake in Manila Trench could cause 32-ft tsunami

A strong earthquake in the Manila Trench—an ocean trench west of the country that runs as deep as 5,400 meters–could trigger tsunamis up to 11 feet tall that would hit Metro Manila in a little more than an hour.

In an interview on "News to Go" aired Thursday, Philippine Institute of Volcanology and Seismology (Phivolcs) Director Renato Solidum said Metro Manila and western Luzon has more than just the West Valley Fault to worry about.

He said that if the Manila Trench shakes and causes a magnitude 8.2 earthquake, western Bataan can expect a wave up to 10 meters tall (around 32 feet) within five to ten minutes.

Tsunami could also hit Occidental Mindoro, Zambales, Batangas and Cavite within minutes, he said.

“Ang [tsunami detection equipment] namin nandito sa Lubang (Mindoro) at Corregidor, tingnan mo yung Lubang, five minutes andoon na. [Sa] Corregidor, mga 40 minutes,” he said.

The same quake could send a tsunami through Manila Bay to hit Malabon, Navotas, Manila and Las Piñas, Solidum said.

“Mahigit isang oras pa ang dating niyan. But yung taas niyan 'pag normal ang sea level ay mga three and a half meters (around 11 feet),” he said.
 

Phivolcs Map of Trenches and Faults

Although it is impossible to predict when an earthquake will happen, a strong earthquake will likely be followed by a tsunami. Among the signs that residents of coastal areas should watch out for are unusual changes in sea level and a rumbling that precedes a tsunami.

A magnitude 8.2 quake hit Chile on Wednesday, prompting state seismologists to monitor sea-level changes for hours. Phivolcs announced Wednesday afternoon that there was no tsunami threat to the Philippines from the Chile earthquake. — Kim Luces/JDS, GMA News