About FaultLineMap.com

FaultLineMap.com provides free earthquake risk reports for any US address using data from the United States Geological Survey (USGS).

Data Sources

• USGS Seismic Design Maps API — Provides ASCE 7-22 seismic design parameters including peak ground acceleration, spectral accelerations, and seismic design categories.
• USGS Earthquake Events API (FDSN) — Real-time and historical earthquake catalog with magnitude, location, depth, and felt reports.
• USGS Quaternary Fault and Fold Database — Locations and characteristics of known fault lines in the US.

How It Works

When you search for an address, we geocode it to coordinates, then query USGS APIs in real time to build your seismic hazard report. The data is always current — we don't cache or modify USGS data.

Disclaimer

This site is for informational purposes only. It is not a substitute for a professional seismic hazard assessment. Building code compliance should be verified with a licensed structural engineer. Data is provided by USGS and may have limitations in coverage or accuracy.