The Philippine Institute of Volcanology and Seismology (PHIVOLCS) has called for wider earthquake preparedness across the Visayas, citing new attention to the Negros Trench, an undersea fault system west of Negros Island capable of generating a magnitude 8.2 earthquake and triggering a tsunami.
PHIVOLCS Director Teresito Bacolcol made the statement during a press briefing on Monday, October 27, held as part of the Handa Pilipinas sa Bagong Pilipinas Expo 2025 (Visayas leg) at the SMX Convention Center in Bacolod City.
Bacolcol said a major quake in the Negros Trench “could generate a tsunami” that may impact western coastlines of Negros, Panay, and parts of Zamboanga and Palawan.
The 400-kilometer Negros Trench, located northeast of the Sulu Trench, has long been part of the country’s seismic map but has received less focus compared to the West Valley Fault in Metro Manila.
Bacolcol said attention on the “Big One” in Luzon should not “overshadow other fault systems” that could also produce destructive quakes. He stressed that preparedness must be nationwide, not just concentrated in the capital.
He reminded coastal residents to be alert for natural tsunami signs such as strong shaking, sudden sea level drop, and a roaring sound from the ocean.
Recent strong earthquakes in Cebu and Davao Oriental have also highlighted the broad seismic activity across the country, reinforcing PHIVOLCS’ call for community-level readiness.
Bacolcol added that other major fault systems — including the Philippine, Manila, Sulu, Cotabato, and East Luzon Trenches — can also generate large-magnitude quakes.
He said modeling shows that a quake along the Philippine Trench could trigger tsunami waves up to 10 meters high in Eastern Samar.
He emphasized that awareness, evacuation planning, and regular drills remain essential for coastal communities. “We cannot prevent earthquakes,” he said, “but we can lessen their impact if we’re prepared.”
Reymund Titong is a Filipino journalist steadily building his voice in the field of news reporting, driven by a commitment to tell meaningful and relevant stories.
He serves as a correspondent for Rappler, maintains a personal blog on Medium, and is the communications officer of Hope Builders Organization Negros Island.