PHIVOLCS: Magnitude 7 to 8 'Big One' quakes also possible outside Metro Manila

BACOLOD CITY – “Big One” earthquakes of magnitude 7.9 up to magnitude 8.2 are possible even outside of Metro Manila, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) said on Monday.

During the HANDA Pilipinas 2025 Visayas Leg Press Conference on Monday, PHIVOLCS Director Dr. Teresito Bacolcol noted that while preparedness and response plans for the “Big One” earthquake are focused on Metro Manila, more devastating quakes are possible in other trenches outside the National Capital Region.

In particular, Bacolcol said Nueva Ecija’s Philippine Fault can generate a magnitude 7.9 earthquake with possible tsunami waves of up to nine to 10 meters, while the 400-kilometer Negros Trench can generate a magnitude 8.2 earthquake.

“Nakafocus tayo sa Metro Manila because it’s the political seat of the government, it’s the economic hub of the country, but nakakalimutan natin that there are bigger ones in other parts of the country,” he said.

(We are focused on Metro Manila because it’s the political seat of the government, it’s the economic hub of the country, but we are forgetting that there are bigger ones in other parts of the country.)

“The world doesn’t revolve around West Valley Fault and marami pang bigger ones in other parts of the country, huwag nating kalimutan. That’s the reason why everybody should prepare… Lahat ng mga Filipinos should prepare kasi hindi lang sa Metro Manila pwede magkaroon ng malaking lindol,” he added.

(The world doesn’t revolve around the West Valley Fault and there are bigger ones in other parts of the country, let’s not forget that. That’s the reason why everybody should prepare… All Filipinos should prepare because it’s not just Metro Manila that can have these big earthquakes.)

Meanwhile, Department of Science and Technology (DOST) Secretary Renato Solidum Jr. clarified that the provided data were only scenarios.

“These are not predictions,” he said.

Solidum explained that while the DOST and PHIVOLCS made preparations for the “Big One” in Metro Manila, they also continued studies and preparations all over the country.

These preparations are also being used in simultaneous earthquake drills nationwide.

“Nationally, the biggest impact would be if there is a movement in West Valley Fault. The exposure is so high in Metro Manila, that’s why we started looking in Manila in 2002 to 2004. In reality, we have studied many cities in the Philippines, we have prepared maps. In fact, we have different scenarios all over the country,” he said.

“Kung di ka taga Metro Manila, paghandaan mo yung lugar mo,” he added.

(If you are not from Metro Manila, make preparations for your area.)

Earlier, Japan and the Philippines announced plans to revisit the “Big One” disaster plans in 2026 to make way for changes, years later after its initial development.

Metro Manila’s “Big One,” which is expected to be magnitude 7.2 or stronger and caused by the West Valley Fault, is projected to result in around 5,000 deaths.

Despite recent concerns about the “Big One” due to recent earthquakes in Cebu and Davao Oriental, the PHIVOLCS clarified that the strong quakes in other parts of the country have no effect or trigger that may cause the West Valley Fault to move. — JMA, GMA Integrated News