If scientists see “The Big One” as the natural disaster that would topple most of Metro Manila and neighboring provinces, Negros Occidental must also be on high alert for a potentially massive earthquake.
At the 2025 Handa Pilipinas Visayas leg in Bacolod City, Philippine Institute of Volcanology and Seismology (PHIVOLCS) director Teresito Bacolcol issued a “stark update,” describing the Negros Trench as a “hidden ticking time bomb” capable of generating a destructive magnitude 8.2 earthquake.
Located northeast of the Sulu Trench and west of the Negros Island Region, the Negros Trench is a 400- kilometer tectonic fault line. On the other hand, the West Valley Fault – the epicenter of the “The Big One” – is a 100-kilometer stretch through Bulacan, Metro Manila, and Calabarzon.
“This fault’s 400-kilometer stretch gives it the energy to spawn a quake that will shake every barangay on Negros — from the sugarcane fields of the north to the coastal fishing villages of the south,” Bacolcol said.
Such magnitude could also trigger tsunami – with waves up to 10 meters high – along the western coastlines of Negros and Panay, and may potentially reach areas as far as Palawan and Zamboanga.
Bacolcol also advised people living near the sea to know the natural signs of a tsunami since it could happen within five minutes of the main strike.
“People should immediately run for higher ground instead of stopping to take Facebook photos,” he added.
Meanwhile, Governor Eugenio Jose Lacson said he will ask officials of towns and cities in Negros Occidental to check their infrastructure if they are capable to withstand earthquakes.
“We should be prepared for the big one but we hope that will not happen,” Lacson told Digicast Negros, adding that all local and provincial government units must prepare should the quake strike.
