Active Faults

An active fault is a crack in the earth's crust that can still move. When it does, the ground directly above it can tear, not just shake. This layer measures the straight-line distance from your property to the nearest mapped active fault.

Distance is everything here. Sitting on top of a fault trace is a legal no-build situation in the Philippines. Sitting a few hundred meters away is survivable but changes how your house must be engineered. We give you the number so the conversation with your engineer starts from fact, not guesswork.

The West Valley Fault runs straight through Metro Manila, under subdivisions, schools, and malls. PHIVOLCS, the government volcano-and-earthquake agency, has warned for years that it could rupture in our lifetime, an event the press calls "the Big One."

A fault setback is not a risk surcharge you can buy your way out of. The National Structural Code of the Philippines (NSCP 2019) bans building within 5 m of an active fault trace, and treats the wider band around it as an advisory zone for critical structures. This layer tells you which side of that line your lot is on.

We measure the nearest-edge distance from your point to the 171 named fault lines using a geography-aware distance query, so the answer is in real meters, not map degrees.

A bounding-box prefilter keeps the query fast even where faults are dense, and the result drops into the band table below.

Fault traces come from the GEM (Global Earthquake Model) active-faults database cross-referenced with PHIVOLCS mapping.

We also run an automatic legal check against the NSCP 2019 setback rule and flag any property inside the 5 m hard buffer or the 500 m advisory band.